Acts 26:8 Meaning

6And now I stand and am judged for the hope of the promise made of God unto our fathers:

7Unto which promise our twelve tribes, instantly serving God day and night, hope to come. For which hope's sake, king Agrippa, I am accused of the Jews.

8Why should it be thought a thing incredible with you, that God should raise the dead?

9I verily thought with myself, that I ought to do many things contrary to the name of Jesus of Nazareth.

10Which thing I also did in Jerusalem: and many of the saints did I shut up in prison, having received authority from the chief priests; and when they were put to death, I gave my voice against them.