Commentaries:
Robertson's Word Pictures (NT)
Believed (episteusen). Ingressive aorist active indicative. Renan considers it impossible that a Roman proconsul could be converted by a miracle. But it was the teaching about the Lord (tou kuriou, objective genitive) by which he was astonished (ekplhssomenov, present passive participle of ekplhssw, see on Matthew 7:28) or struck out as well as by the miracle. The blindness came "immediately" (paraerhma) upon the judgment pronounced by Paul. It is possible that Sergius Paulus was converted to Christ without openly identifying himself with the Christians as his baptism is not mentioned as in the case of Cornelius. But, even if he was baptized, he need not have been deposed from his proconsulship as Furneaux and Rackham argue because his office called for "official patronage of idolatrous worship." But that could have been merely perfunctory as it probably was already. He had been a disciple of the Jewish magician, Elymas Barjesus, without losing his position. Imperial persecution against Christianity had not yet begun. Furneaux even suggests that the conversion of a proconsul to Christianity at this stage would have called for mention by the Roman and Greek historians. There is the name Sergia Paullina in a Christian cemetery in Rome which shows that one of his family was a Christian later. One will believe what he wills about Sergius Paulus, but I do not see that Luke leaves him in the category of Simon Magus who "believed" (Acts 8:13) for revenue only.
Other Robertson's Word Pictures (NT) entries containing Acts 13:12:
Acts 8:9
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