John Calvin in Calvin's Commentaries:
When they heard these things they fell silent. And they glorified God, saying, Then to the Gentiles also God has granted repentance that leads to life. – Acts 11:18
Whosoever will rightly profit in the gospel, let him put off the old man, and think upon newness of life, (Ephesians 4:22;) that done, let him know for a certainty that he is not called in vain unto repentance, but that there is salvation prepared for him in Christ. So shall it come to pass, that the hope and assurance of salvation shall rest upon the free mercy of God alone, and that the forgiveness of sins shall, notwithstanding, be no cause of sluggish security.