John Calvin on Acts 13:12

12. Then when the deputy saw This is that which I said, that the snares were broken wherein Elymas kept him entangled, for he was brought by the miracle unto faith, because the reverence of doctrine is the beginning of faith, and the preparation. Therefore, forasmuch as he saw an evident token of the power of God, he knew that Paul was sent of God, and so he began to reverence his doctrine, whereof he did doubt before. If God do now miraculously strengthen in the minds of many the faith of the gospel, which is shaken with so many and such strong engines; if he bring to pass, after an incredible manner, that the course of faith doth pass through a thousand lets, being content with this his grace, let us not murmur against him, or reason the matter with him, as if our condition were worse, if he do not daily show such miracles as we would desire.

Acts 13:13-15

13. And when Paul’s companions had loosed from Paphos, they came to Perga of Pamphylia; and John departing from them returned to Jerusalem. 14. Furthermore, when they had passed over the country of Perga, they came to Antioch, a city of Pisidia, and entered into the synagogue upon the day of the Sabbaths, and sat 15. And after the lecture of the law and prophets, the master of the synagogue sent to them, saying, Men and brethren, if there be in you any word of exhortation unto the people, say on.