Make witness of what I have received and experience from the Lord

Acts 22:12-21
The Lord said to Paul, "Go ; I will send you far away to the Gentiles."
But the mention of his mission to the Gentiles creates a fresh furore(轟動)
Why?
Paul left Jerusalem for he followed the instruction of the Lord to preach gospel to the Gentiles. Because the people in Jerusalem won't listen to his word and Paul afraid that he had persecuted those who believed in Jesus. Now he returned to Jerusalem to make witness of what he received the mission of the Lord.
Paul wanted to prove what he did is same as the apostle received from Jesus Chris in Jerusalem.
Paul suffered is same as Jesus Christ rejected in his home town. Paul follow the way of Jesus Christ had walked.
How?
Do what God leads me,  make witness what I saw and what I heard and what I have experienced to others.