Acts 3:16

And by faith in his name hath his name made this man strong, whom ye behold and know: yea, the faith which is through him hath given him this perfect soundness in the presence of you all.

In this verse appears the only mention of faith in this whole narrative; and it is mentioned here, not as a condition of receiving salvation (although it is so, of course) but as an explanation of the power that had healed the cripple, the faith in view being not of the cripple at all, but of the men who healed him. Following this explanation, Peter went on with his sermon; and, somewhat later, when again he would announce terms of redemption to men, his words (Acts 3:19) were in perfect agreement with what he had announced on Pentecost. The conceit that Peter's mention of faith in this verse was due to his having discovered by some means or other that baptism was no longer a condition of salvation is founded upon a denial of the sacred text. The terms of redemption are not in view at all in this verse; but what is taught is that the apostles (already saved) had performed this wonder by reason of their faith in Jesus Christ; and, at this point in the narrative, Peter had not told either the healed beggar or the multitude what to do to be saved. He would do that later (Acts 3:19). Another important corollary of this verse is:

The power of performing miracles was given to the apostles by virtue of the baptism of the Holy Spirit, but they needed to exercise faith before this power could be used.[13]