According to the 'Acts of the Apostles', Paul (then still called Saul) was actively prosecuting the followers of Jesus, which by many were considered to be a Jewish sect, like there were more of such sects.
It was on one of this prosecution trips that he experienced a medical condition that lead to temporary blindness, which he interpreted as a divine intervention, resulting him to join the sect.
It was on one of this prosecution trips that he experienced a medical condition that lead to temporary blindness, which he interpreted as a divine intervention, resulting him to join the sect.