For I have appeared to you for this purpose

Acts 26:16
But rise and stand on your feet; for I have appeared to you for this purpose, to make you a minister and a witness both of the things which you have seen and of the things which I will yet reveal to you.

Paul encountered the risen Lord and his entire life changed. He had only one purpose and that is to do the will of God as revealed in Yshua. The encounter itself may have been short, and Jesus said few words. There was no doctrine or theology being taught, no correction to Paul intellectual knowledge. It was just Yshua revealing Himself. That was enough to change the life of Paul.

Although many of us do not have the Jesus encounter that Paul did, when we believe, the Holy Spirit did come into us. It is not by our own wisdom or understanding that we chose Christ, but He chose us. Having been chosen, we still must will ourselves to live for Christ.