on Acts 8 :13
Simon himself believed also - He was struck with the doctrine and miracles of Philip - he saw that these were real; he knew his own to be fictitious. He believed therefore that Jesus was the Messiah, and was in consequence baptized.
Continued with Philip, and wondered - ΕξιϚατο, He was as much astonished and confounded at the miracles of Philip as the people of Samaria were at his legerdemain. It is worthy of remark that εξιϚατο comes from the same root, εξιϚημι, as the word εξιϚων, in Acts 8:9, and, if our translation bewitched be proper there, it should be retained here; and then we should read, Then Simon himself believed and was baptized, and continued with Philip, being Bewitched, beholding the miracles and signs which were done. We may see, from this circumstance, how improper the term bewitched is, in the 9th and 11th verses.
on Acts 8 :13
Then Simon himself believed also - That is, he believed that Jesus had performed miracles, and was raised from the dead, etc. All this he could believe in entire consistency with his own notions of the power of magic; and all that the connection requires us to suppose is that he believed this Jesus had the power of working miracles; and as he purposed to turn this to his own account, he was willing to profess himself to be his follower. It might have injured his popularity, moreover, if he had taken a stand in opposition when so many were professing to become Christians. People often profess religion because, if they do not, they fear that they will lose their influence, and be left with the ungodly. That Simon was not a real Christian is apparent from the whole narrative, Acts 8:18, Acts 8:21-23.
And when he was baptized - He was admitted to a "profession" of religion in the same way as others. Philip did not pretend to know the heart; and Simon was admitted because he "professed" his belief. This is all the evidence that ministers of the gospel can now have, and it is no wonder that they, as well Philip, are often deceived. The reasons which influenced Simon to make a profession of religion seem to have been these:
(1) An impression that Christianity was "true." He seems to have been convinced of this by the miracles of Philip.
(2) the fact that many others were becoming Christians; and "he" went in with the multitude. This is often the case in revivals of religion.
(3) he was willing to make use of Christianity to advance his own power, influence, and popularity - a thing which multitudes of men of the same mind with Simon Magus have been willing since to do.
He continued ... - It was customary and natural for the disciples to remain with their teachers. See Acts 2:42.
And wondered - This is the same word that is translated "bewitched" in Acts 8:9, Acts 8:11. It means that he was amazed that Philip could "really" perform so much greater miracles than "he" had even pretended to. Hypocrites will sometimes be greatly attentive to the external duties of religion, and will be greatly surprised at what is done by God for the salvation of sinners.
Miracles and signs - Greek: signs and great powers, or great miracles. That is, so much greater than he pretended to be able to perform.
on Acts 8 :13
8:13 And Simon believed - That is, was convinced of the truth.