Acts of the Apostles has three, somewhat different accounts of the conversion of Paul on the road to Damascus - Acts 9:3-8, 22:6-11 and 26:12-19. Not only does Paul never mention this experience, but it differs in material respects from what Paul does say about his conversion.
If Luke did not learn of this from Paul, he might have been inspired to write this story by another source. Uta Ranke-Heinemann, author of Putting Away Childish Things claims that parallels between Acts and the Bacchae mean that the story of Paul's conversion could have been inspired by the play.
For example, she says that the parallel passage has the god Dionysus complain to Pentheus about persecution, just as Jesus complains to Paul about persecution. A well known saying among Greeks and Romans, but apparently never used by Jews, was "kick against the goads," the goad being a prod used to keep an ox working - painful if you kick against it. She asks why Jesus would use a Greek saying to Paul, a Jew who would probably not understand it, and why Jesus would pointedly speak this Greek saying "in the Hebrew language" when we know he was quite fluent in Greek Koine.
The text appears to be of Greek cultural origin. What is the evidence for this being specifically from the Bacchae.