Is Baptism required for Salvation?
Due to the differing views within Christendom today regarding the subject of baptism, it might be helpful to clarify whether we are talking about the substance of baptism or the symbol of baptism. It is very common today for many to substitute the symbol for the substance. Whenever a text (such as John 3 or Romans 6) talks about the substance of baptism (being "born again" or "immersed" into Christ) the scripture would confirm that indeed the substance of baptism is necessary; for there is salvation in no other (Acts 4:12).

As Christ said to Nicodemus, you must be "born again" to enter the kingdom of heaven (John 3:3). The O.T. taught again and again that the hope of the kingdom of God was not due to the work of men but the sovereign work of a holy God who would give men a new heart. The Lord said to the people in Ezekiel 36 that He would, at the coming of the Messiah, wash their bodies with clean water and give them a new heart. He would put His Spirit in them that they might walk in His ways. When a person is saved by the operation of grace; He washes them clean and fills them with the Holy Spirit.

“Not by works of righteousness which we have done, but according to His mercy He saved us, through the washing of regeneration and renewing of the Holy Spirit.” Titus 3:5

Can you be baptized by water and still be in need of spiritual cleansing?
Absolutely, it has happened a lot throughout history. This was the problem within Catholicism that has now been carried over into Protestantism. There are those who will get baptized in water without ever being washed by the word in repentance or being made new from within by the work of the Holy Spirit; thus they will cling to the physical symbol of water baptism though there is no spiritual substance of "new birth" in Christ. They will recall the day they got water baptized and expect God to save them because they went through some ceremony or ritual of being dipped in water, yet there is no evidence anything has actually occurred within their heart.

They are what is sometimes called "shell" Christians. They look good on the outside; they talk the talk; and they do the stuff that makes them appear religious, but their hearts are far from being right with the Lord, because there is no true repentance, no turning from sin, no substantive change in the way they think or live. They have embraced all the trappings of religion with no inward transformation. This is the primary cause for arguments and division within churches.

Water baptism can't cleanse the soul but it is the physical symbol of spiritual cleansing. That is why John the Baptist was baptizing people in water as a symbol of their inward repentance.

Why does Peter say that “baptism … now saves us” (1 Peter 3:21)?
To properly understand this text you have to first keep it within its context. The verse that precedes it says “...because they formerly did not obey,  when God's patience waited in the days of Noah,  while the ark was being prepared, in which a few, that is,  eight persons, were brought safely through water.” 1st Peter 3:20

Wickedness may appear to flourish because of the long suffering of a patient God, but we are to remain steadfast in righteousness even if it requires unjust suffering because ultimately a sovereign God will make all things right.

Do as Noah did, take God at His word and remain faithful to your calling; trusting the Lord for your deliverance. The Lord patiently waited 120 years in the days of Noah and only eight people stepped into the ark, that which would bear them up when the rains came. Though they had never seen rain before what the Lord said would take place came to pass.

Now let's deal with verse 21: "Baptism, which corresponds to this,  now saves you, not as a removal of dirt from the body but as an appeal to God for a good conscience,  through the resurrection of Jesus Christ."

Peter says, "baptism which corresponds to this" the point he just made in the previous verse. Baptism is an antitype (an earthly expression for a heavenly reality) which now saves us ... "not the removal of filth from the flesh but the answer of a good conscience toward God, through the resurrection of Jesus Christ.”

This is called an antitupon, an OT prefiguring of what will come true in the N.T. Just as Noah trusted in the Lord and His word and that faith was found to be victorious; in the same way we are to trust in Christ by the word of God and our faith in Him will be found victorious.

Just like Noah we are to stand in this thing made of wood, the cross, and when the wrath of God comes in the final day against the sins of men we will be raised up above the judgment and will find deliverance just as those eight people experienced in the days of Noah.

Peter is speaking to the substance of baptism? We die to our old self and past, buried in Christ then raised to walk in a newness of life in Him. Salvation is when we are immersed in the One who made atonement for sin at the cross (Romans 6:1-4).

So we must not miss the point of the antitupon and think that an external ritual like water baptism is what saves us. Don't be misled into believing that a physical ceremony can produce a spiritual result. The antitupon is a type; Noah's trust was in the Lord; that is what led him to enter the ark which raised him above the waters of judgment. And it is our trust in the Lord that leads us to enter into Christ by grace through faith and He is the One who lifts us above the waters of judgment; when we are immersed in Him (speaking of our soul not the external dipping of our body in water) we will sail above the holocaust of judgment for sin.

So that we won’t think some ceremony administered by man can reconcile us to God, Peter says I'm not talking about the washing of your body but the spiritual appeal to God for a good conscience. God who is holy is not impressed with wet sinners.

What redeems, reconciles, and delivers sinners is being born again in Christ. When we are immersed in Him we will be raised from the dead just as He was, which is what water baptism is meant to signify.

To add any ritual to what Christ accomplished at the cross leads to the kind of heresy that plagued the church throughout the Dark Ages. It denies what Christ said from the cross: "It is finished". He alone satisfied the just wrath of God for sin and only those (born again, John 3:3) "immersed" in Him will stand before God justified.

If the ritual of water baptism does not save, is it important for believers to be baptized in water?
Absolutely! Water baptism is meant to identify new Christians with the death, burial and resurrection of Jesus Christ (Romans 6:1-10; Colossians 2:12).

Water baptism outwardly symbolizes the inward cleansing that has taken place in the life of a believer as well as their deliverance from sin's just punishment (Acts 22:16; 1 Peter 3:20-21).

Both Christ and the apostles commanded believers to be baptized because it is a visual representation of what spiritually has occurred.

While water baptism is a part of our sanctification process (one who is born again in Christ will become more like Him through obedience to His word) it was never meant to be the means of salvation.

Catholicism and some protestant denominations teach what is called sacramentalism, which is an act that a person performs, and through which, the grace of God is conferred to them; therefore, it is taught that God's grace is administered through receiving the sacraments of the church. However, whenever any part of scripture is understood within the whole of scripture, it is clear that only Christ's atoning death can reconcile sinners with a holy God; thus our faith and trust is in Him, not in the observance of a sacrament, is God's means for our redemption.

Our new birth is portrayed in water baptism, but not performed by water baptism.

Should a child be baptized at birth? Why do some churches christen newborns? How can we know when a child should be baptized? If a child of Christian parents dies, what is the child's fate in eternal life?

Geoffery Bromiley’s book, “Children of Promise,” considered by many to be the best defense for infant baptism, admits there is no real evidence that infants were baptized in the churches of the New Testament. Some suggest the household baptisms in Acts may have included infants, but this is speculative at best. In the case of the Philippian jailer the Scripture says, “They spoke the word of the Lord to him together with all who were in the house” (Acts 16:32), which seems to indicate all in his home were old enough to hear the gospel message.

Throughout the New Testament, baptism followed immediately after a believer expressed confidence in Christ, as a witness of his faith (Acts 2:38).

So when did the christening of newborns begin?

Early church leaders such as Irenaeus, who wrote a five-volume treatise on theology, made no reference to infant baptism (paedobaptism). The Epistle of Barnabas in the second century mentions only the baptism of believers. It is not until the earliest part of the third century that Tertullian, a leader in the church in North Africa, argued against the baptism of infants, “insisting that children should come for baptism when they understand what they are doing” (Edwin Lutzer, “Doctrines that Divide” p. 119). Tertullian’s objection indicates that paedobaptism had begun, in at least some churches, by the year 200.

Cyprian, also from North Africa, links infant baptism with spiritual regeneration in 251, but adds that babies should also be given communion (the first signs of sacramentalism, which stresses that salvation comes through the church’s channels of grace as the sacraments are administered). Augustine, a fourth century theologian from North Africa, taught that both sacraments (communion and baptism) were necessary for salvation; therefore, both should be administered for infants (Paul Jewett, “Infant Baptist and the Covenant of Grace" p. 40). Today, sacramentalists still believe a baby who dies un-baptized will go to hell, or at least his eternal destiny is in doubt, which is the reason a priest is quickly called to perform the ritual when a baby’s life is in jeopardy.

With the development of christening, the idea of having parents sponsor the child began, a practice Tertullian also opposed.

The practice of paedobaptism and the giving of communion to infants apparently began in North Africa around the year 200 due to the belief that forgiveness of sins came through administering the sacraments of the church.

Once Constantine overcame the Roman ruler, Maxentius, in 312, Christians were no longer to be persecuted, but their faith was to now be embraced by the government. Christianity would become synonymous with the Roman Empire and infant baptism became the link by which the church and the state were united. Though paedobaptism began due to the theological convictions of some (who believed the ritual washed away the effects of sin), every child would now to be christened (made a Christian by participating in a ritual) both a member of the church and a member of the Roman Empire. Therefore, Anabaptists (those re-baptized as adults because they refused to believe that a baptism which embraces everyone could be valid) were severely persecuted not just for theological reasons, but for political purposes. By the time of Charlemagne (800 A.D.) those who were re-baptized after coming to faith in Christ were put to death, because infant baptism was the glue that united the church and state and the power of the state enforced the religion of the state.

By the time of the Reformation, some reformers were having serious doubts about infant baptism. Ulrich Zwingli, the people’s priest in Zurich, initially confessed that it grieved him to baptize infants. “I call it neither right or wrong; if we were to baptize as Christ instituted it, then we would not baptize any person until he has reached the years of discretion; for I find it nowhere written that infant baptism is to be practiced” (Leonard Verdium, “The Reformers and Their Stepchildren” p. 198). However, by 1525 Zwingli had changed his mind after he viewed Anabaptists as being disruptive to the social order and he believed he may have found theological grounds to support the practice of infant baptism (explained below).

Since Martin Luther believed justification was by faith alone, to defend the practice of infants being regenerated by baptism he suggested in his commentary on Galatians that infants can hear the gospel and believe easier than adults. He never gave up the practice of paedobaptism, but explained: “There is not sufficient evidence from Scripture that one might justify the introduction of infant baptism at the time of the early Christians after the apostolic period, but so much is evident that no one may venture with good conscience to reject or abandon infant baptism, which for so long time has been practiced” (Verdium, p. 204).

Zwingli and John Calvin, who also admitted there was no record in Scripture of infants being baptized, believed they found theological support for paedobaptism when they proposed a relationship between the Old Testament sign of circumcision and the New Testament sign of baptism. They contended that the rite of circumcision, which was administered to all Jewish males on the eighth day, proves that God’s blessings are bestowed on children as well as their parents. Calvin would later teach baptism does not effect the regeneration of infants, but is only a sign that the “seeds of repentance lie in infants by the secret working of the Spirit.” Therefore, infant baptism is a sign of the New Covenant just as circumcision was the sign of the Old Covenant (Col. 2:11-12), which is today referred to as Covenant Theology. Baptism is therefore not a sign of the child’s faith, but rather a sign of what the parents believe or hope God has done or will do for that child.

However, since some children who had been baptized as infants did not embrace the Christian faith as they grew older, confirmation was instituted to confirm the decision the parents had made for their children. Therefore, baptism to them was the outward sign of the grace an infant will receive if he grows up and believes.

Many theologians could not embrace this explanation, but pointed to the Catechism of the Church of England that claimed infants became a child of God and a member of the church by means of infant baptism. They contended that circumcision was a sign of earthly, temporal blessings the Lord gave to the Israelites (offspring of Abraham) that pointed to the ultimate spiritual benefits for those who would believe. However, in the church, one’s genealogical record does not guarantee such special blessings and baptism is certainly not the regenerative agent for bringing one to a saving faith in Christ.

Charles Spurgeon, a famous preacher of the nineteenth century, in his opposition to the practice of infant baptism, declared . . . since no outward ceremony can save anyone and parents cannot believe for their children, the practice of infant baptism should be abandoned within the Protestant Church. He urged all who may be resting their hope of salvation on this rite to “shake off this venomous faith into the fire, as Paul did the viper which fastened to his hand.”

Spurgeon and many others believed the N.T. clearly taught that those who had been regenerated from spiritual death unto life, who had placed their faith in Christ and His atoning work at the cross and who were willing to repent of their sins were the ones who should be baptized in the name of the Father, Son and Holy Spirit by immersion, as a sign of being united with Christ in His death, burial and resurrection (Mark 16:16, Acts 2:38, 8:12, 8:36-39). This is known as believer’s baptism.

As for your question about babies who die, most believe those children go to heaven. However, if that is true, it is not because they are born innocent or their baptism at birth washes away the effects of their sinful nature. Salvation is of the Lord, so everyone (including infants) who is saved is redeemed by God’s sovereign mercy and grace through Christ’s atoning death at the cross. The salvation of all infants is in the hands of the Lord, not in the hands of men who administer a ritual.

Conclusion:

Should a child be baptized at birth? There is no clear teaching from Scripture advocating or commanding this practice. However, for those who choose to accept the proposal that infant baptism is a sign of the New Covenant just as circumcision was the sign of the Old Covenant and that baptism is not a sign of the child’s faith, but rather a sign of what God has done or will do for that child, this practice provides some comfort; however, it is not the belief or practice at Wellington.

Why do some churches christen newborns? They either believe baptism to be the regenerative means of removing sin’s effect upon the life of a child, which provides or guarantees salvation or they embrace the propositions of Covenant Theology as suggested by Zwingli and Calvin.

How can we know when a child should be baptized? When a child believes in Christ and trusts in His atoning work at the cross.

If a child of Christian parents dies, what is the child's fate in eternal life? Salvation is of the Lord, so everyone (including infants) who is saved is redeemed by God’s sovereign mercy and grace through Christ’s atoning death at the cross. The salvation of all infants is in the hands of a loving, merciful, gracious, holy, and righteous God. For us to speculate beyond what scripture clearly teaches is an exercise in futility and may lead to a false understanding of His truth.