John Calvin Commentary 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." — Acts 3:16 (ASV)

And in the faith of his name. When he says, in the faith of his name, and his name; and again, the faith which is by him; this repetition is a sign of fervent affection, because he was wholly devoted to setting forth the glory of Christ, he repeatedly emphasizes the same thing.

Moreover, we see that when Paul is occupied with showing and setting forth the grace of Christ, he thinks that he has never spoken enough about it. And surely, such is the wicked nature of humanity, that Christ cannot be so highly extolled and preached that His honor remains fully intact for Him.

Let us, therefore, remember that Peter used such variety and abundance of words so that he might keep us steadfast in Christ. Regarding the phrase, when he says, his name in the faith of his name hath strengthened, he shows both the cause and the manner: the power of Christ had healed the cripple, but by faith.

When he says, the faith which is by him, by these words he signifies to us that our faith cannot ascend to God unless it is grounded in Christ, and so, consequently, that our faith looks to Christ and rests itself upon Him. And so he shows that there can be no true faith in God when we bypass this means.

Furthermore, as he said before that he and the other apostles were witnesses of Christ’s life, so he now declares that this life was clearly proven to the Jews by a sign or effect, because they saw the cripple healed, in whom they had an excellent and evident sign of the divine power of Christ. And when in this last phrase he makes faith the cause of this soundness, he incidentally charges them with unthankfulness unless they give faith her due praise; and although faith may be referred both to the man who was healed and to the apostles, yet we need not dwell much on this matter, because the power of the gospel is set forth by synecdoche.