But Barnabas got hold of him and introduced him to the apostles, and he told them how on his journey he had seen the Lord, and that he had spoken to him, and how boldly he had spoken for the cause of Jesus at Damascus.

and spoke boldly for the Lord's cause, talking and debating with the Greek-speaking Jews. But they tried to kill him.

I once thought it my duty vigorously to oppose the cause of Jesus of Nazareth.