Good morning sir,
Please, I need your help in explaining Acts 2:39 because someone I am discussing it with is trying to use that passage as a backup for infant baptism. He said that Acts 2:38-39, according to the Greek translation, means babies should be baptized according to their parents' faith.
Let's first examine what we do know about the baptism in Acts 2.
The choice for being baptized was made by the people being baptized. "So then, those who had received his word were baptized; and that day there were added about three thousand souls" (Acts 2:41). Their choice was based on accepting Peter's teaching. Thus, we know that these people had heard Peter's sermon (Acts 2:37,40) and believed what Peter taught (Acts 2:37,41). One of the things that Peter taught them was that they had to repent (Acts 2:38).
Therefore, we must conclude that there were no infants among the 3,000 who were baptized that day because no infant fully understands language, no infant can believe, and no infant has sins to repent of doing.
This baptism was for the remission of sin (Acts 2:38), to receive the gift of salvation from the Holy Spirit (Acts 2:39), and to be added to the church (Acts 2:47). Peter commanded the crowd to be baptized (Acts 2:38,40) but the command wasn't just for the immediate audience. "For the promise is for you and your children and for all who are far off, as many as the Lord our God will call to Himself" (Acts 2:39).
Now notice how your friend twisted Acts 2:39. Peter said was for as many as the Lord God calls to Himself. Your friend said it was the parents who decided to baptize their children. Peter shows that this calling requires the people responding to make a choice. Your friend says the infant has no choice in the matter.
The phrasing is that the command to repent and be baptized will continue generation after generation. Peter is not just talking about their immediate children. Peter is also indicating that the command is not limited to just the Jews. It was for those present and those far off. This is a global command that will last through the ages.
Therefore, we conclude that your friend's assertion doesn't match the text. The mistake he made is that he asserted a possibility and then claimed that the text required that possibility to be true. Assumptions are not proof, nor are they necessarily required. In this case, his assumption doesn't fit the context so it is false.