We had a life before we accepted Jesus Christ as Lord. Paul was killing the Christians. God stopped Paul because he was radical during the wrong thing [killing the Christians]. God knew Paul would be just as radical saving souls. Paul view his calling to preach the same way he viewed his order to kill the Christians. However, it was completely different because Christ revealed Himself to Paul leading and guiding Paul to do what was needed to build God's Kingdom. I feel after been left with no sight he was ministered to from God which thinking of his old life he knew that he had to be obedient; so no choice was involved. Paul just submitted to God. He did not look at this change in his life as something to be honor but only to obey. As for me it helps me to just do what is right in the eyes of the Lord regarding God's gifting and calling us for ministry. The opposite of unfaithfulness towards God's gifts are abuser, disloyalty, and not grateful because it is an honor to be used by God for His Glory to be revealed to people.