First, I disagree with you that baptism is not a condition of salvation!
Jesus said, "He that believes and is baptized shall be saved". (Mark 16:16) Peter said repentance and baptism are "for the remission of your sins" ("unto the remission of sins" - ASV) (Acts 2:38). Peter also said "baptism now saves". (1 Peter 3:21) Paul said that at baptism we enter "into Christ" (Galatians 3:27, Romans 6:3-13). He also said we contact Christ's death. That is where the saving blood was shed. (Romans 5:8-10) When we contact that blood, our sins are washed away. (Acts 22:16, Revelation 1:5)
The doctrine of infant baptism comes from the (mistaken) idea that babies have the guilt of sin, therefore they need to be baptized to wash away that sin.
Again, the Bible does teach that baptism has a role in having our sins washed away (Acts 22:16) by bringing us “into Christ” and figuratively into contact with His death, where the saving blood was shed (Romans 6:3-4, Galatians 3:27, Colossians 2:12). It is that blood that washes away sins (Romans 5:8-10, Revelation 1:5), yet it is through baptism that we contact the blood, therefore, “baptism now saves… through the resurrection of Christ” and baptism is “for the remission of sins”. (1 Peter 3:21, Acts 2:38, Mark 16:16)
Finally, it is at baptism that we “rise to walk in newness of life” (Romans 6:3-13, Colossians 2:12). We cannot be saved if we are not “born again” into this new life in Christ.
Infants, however, do not need to be baptized, and they are not candidates for scriptural baptism, for the following three reasons:
First infants are not born with the guilt of inherited sin, so they do not have any inherited sin (guilt) that needs to be forgiven. Ezekiel 18:20 says, “The soul that sinneth, it shall die. The son shall not bear the iniquity of the father, neither shall the father bear the iniquity of the son: the righteousness of the righteous shall be upon him, and the wickedness of the wicked shall be upon him.” Infants are born in a safe condition.
We will each be judged based on what we have done, not based on how anyone else has lived. 2 Corinthians 5:10 says, “For we must all appear before the judgment seat of Christ; that every one may receive the things done in his body, according to that he hath done, whether it be good or bad.”
Secondly, infants do not have any sin of their own. 1 John 3:4 says, “Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.”
Since “sin is the transgression of the law”, if a baby is guilty of sin, what law have they transgressed, or which law are they even capable of transgressing or even understanding? Clearly, a baby has transgressed no law!
Finally, baptism in the New Testament is preceded by belief and repentance. (Mark 16:16, Acts 2:38)
In Acts 8, the eunuch asked, “…What hinders me from being baptized?” (verse 36) The answer was, “If you believe with all your heart, you may.” (verse 37)
An infant is not able to believe, therefore, they are not candidates for baptism.
An infant has no personal or inherited sin (guilt), so they do not need baptism. Also, since they do hot have the capacity to believe and repent (and they have nothing to repent of), they do not meet the requirements in order that they may be baptized.
Also, Biblical baptism is by immersion. It would be difficult to safely, completely immerse an infant.
The New Testament was originally written in the Greek language. The Greek word we get the word "baptism" from, means to immerse.
Immersion is to dip down into the water. It is an overwhelming. The one being baptized is lowered into (until he is completely under) the water and then lifted up out of the water. It is not just sprinkling or pouring a little water on top of someone.
This can also be seen in Scripture.
John 3:23 says, "Now John also was baptizing in Aenon near Salim, because there was much water there. And they came and were baptized." Only immersion requires "much water".
Baptism is described as going down into the water and coming up out of the water. (Matthew 3:16-17, Acts 8:38-39) Only immersion has the one being baptized going into the water.
Also, baptism is described as a burial. (Romans 6:3-4, Colossians 2:12) Only immersion buries the one being baptized.
It's funny that the only place that people have trouble understanding baptism is in religion. If someone were to say they were "baptized in debt", would you think they had just a sprinkling of debt (a few bills)? No, someone described in this way is figuratively "covered up" with debt.
I saw a sports article that said the freshmen on a football team had an "early baptism". Of course it mean they were plunged into full sudden participation in the program. They did not just see a sprinkling of activity, but they were fully involved.
If we can understand this everywhere else, why not in religion?
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Those who teach infant baptism many times point to the households that were baptized in the New Testament. They assume these households had infants and those young children were included in the baptism.
This, however is just an assumption. It is risky to base your doctrine on a guess that cannot be proven from the Scriptures!
In fact, the context of many of these scriptures DISPROVE infant baptism. Notice for example the household of the keeper of the prison in Acts 16.
He was baptized with his household (verse 33). But notice also, all his household was taught ( verse 32), and they all believed (verse 34). An infant cannot be taught, and an infant cannot believe. Therefore, "household" here did not include any infants.