Next, is the well known figure of St. Justin Martyr (c. 100-165). Here are some selections from his First Apology:
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. They then 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. . . . The reason for this we have received from the Apostles. (Chapter 61)
Notice that Justin Martyr, writing about fifty years after the death of the Apostle John, claims that they received from the Apostles the doctrine that through baptism they receive remission of sins that are past [i.e. prior to baptism], and through baptism they are regenerated in the same manner that all Christians were regenerated (i.e. by baptism).