When it comes to the issue of baptism, there is not a little disagreement among Christians. I am, as many of you will know, a baptist. I believe that the Bible is clear about baptism. I think it is easy to demonstrate it is an initiatory act that is supposed to follow faith, and hence cannot be performed on infants.
I believe that baptism is the primary way a new believer is commanded by Jesus himself to dedicate themself to God. I believe that it requires much water and is to be performed by immersion, meaning the subject is washed by water.
I could support each of those assertions by Scripture and I have never read a convincing argument for why we should set aside the plain teaching of The Bible. As much as I respect as genuine believers many who think differently to me, I remain convinced of the baptist position.
Although we can and should primarily argue this issue on the grounds of Scripture, there is another arena we need to engage. There is an assumption by many in the other camp that the church has always sprinkled babies instead of immersing adults, or at least those old enough to have determined to follow Jesus for themselves. Today I want to demonstrate that the early church was in fact baptist. It is true that by the third century infant baptism was practiced. But there are two important pieces of data from the AD100s that suggest that earlier baptism was reserved for those who actually believed for themselves. The first is the Didiche that requires baptismal candidates to fast (something that would be impossible for an infant. The second is a much neglected early hero of the church, Justin Martyr, the first to write an apologetic for the faith. He writes around 150AD the following clear articulation of a baptist view:
I will also relate the manner in which we dedicated ourselves to God when we had been made new through Christ; lest, if we omit this, we seem to be unfair in the explanation we are making. As many as are persuaded and believe that what we teach and say is true, and undertake to be able to live accordingly, are instructed to pray and to entreat God with fasting, for the remission of their sins that are past, we praying and fasting with them. Then they are brought by us where there is water, and are regenerated in the same manner in which we were ourselves regenerated. For, in the name of God, the Father and Lord of the universe, and of our Saviour Jesus Christ, and of the Holy Spirit, they then receive the washing with water. For Christ also said, Unless you be born again, you shall not enter into the kingdom of heaven. John 3:5 Now, that it is impossible for those who have once been born to enter into their mothers’ wombs, is manifest to all. And how those who have sinned and repent shall escape their sins, is declared by Esaias the prophet, as I wrote above; he thus speaks: Wash you, make you clean; put away the evil of your doings from your souls; learn to do well; judge the fatherless, and plead for the widow: and come and let us reason together, says the Lord. And though your sins be as scarlet, I will make them white like wool; and though they be as crimson, I will make them white as snow. But if you refuse and rebel, the sword shall devour you: for the mouth of the Lord has spoken it. Isaiah 1:16-20
And for this [rite] we have learned from the apostles this reason. Since at our birth we were born without our own knowledge or choice, by our parents coming together, and were brought up in bad habits and wicked training; in order that we may not remain the children of necessity and of ignorance, but may become the children of choice and knowledge, and may obtain in the water the remission of sins formerly committed, there is pronounced over him who chooses to be born again, and has repented of his sins, the name of God the Father and Lord of the universe; he who leads to the laver the person that is to be washed calling him by this name alone. For no one can utter the name of the ineffable God; and if any one dare to say that there is a name, he raves with a hopeless madness. And this washing is called illumination, because they who learn these things are illuminated in their understandings. And in the name of Jesus Christ, who was crucified under Pontius Pilate, and in the name of the Holy Ghost, who through the prophets foretold all things about Jesus, he who is illuminated is washed.
Source: Chapter 62 of The First Apology.