That Christian baptism required an understanding of God’s Word and an intelligent decision to present oneself to do the revealed will of God was evident when, at Pentecost, 33 C.E., the Jews and proselytes there assembled, who already had a knowledge of the Hebrew Scriptures, heard Peter speak about Jesus the Messiah, with the result that 3,000 “embraced his word heartily” and “were baptized.” (Ac 2:41; 3:19–4:4; 10:34-38)

At Pentecost, Jews who bore community responsibility for Jesus’ death, and who doubtless knew of John’s baptism, were “stabbed to the heart” by Peter’s preaching and asked: “Brothers, what shall we do?” Peter answered: “Repent, and let each one of you be baptized in the name of Jesus Christ for forgiveness of your sins, and you will receive the free gift of the holy spirit.” (Ac 2:37, 38) Notice that Peter pointed out something new to them​—that, not repentance and baptism in John’s baptism, but repentance and baptism in the name of Jesus Christ was necessary for forgiveness of sins. He did not say that baptism itself washed away sins. Peter knew that “the blood of Jesus [God’s] Son cleanses us from all sin.” (1Jo 1:7) Later, after speaking of Jesus as “the Chief Agent of life,” Peter said to Jews at the temple: “Repent, therefore, and turn around so as to get your sins blotted out, that seasons of refreshing may come from the person of Jehovah.” (Ac 3:15, 19) Here he instructed them that repenting of their bad deed against Christ and ‘turning around,’ to recognize him, was what brought forgiveness of sin; he did not at this point mention baptism.