Paul was struck to the ground and had to hear from Jesus directly. He had to be asked, "How long will you kick against the goads?" The reference there is to a sharp stick (goad) used to urge beasts of burden forward. Kicking against them will only hurt, not get rid of them. If Paul had continued in his rigid and strong opposition to the message of Jesus, it would have served only to cause himself great harm. Jesus wasn't going away.
