Paul, a servant of Christ Jesus, called to be an apostle and set apart for the gospel of God - this gospel God promised beforehand through his prophets in the Holy Scriptures. Specifically, this promise was in regard to his Son, who in the flesh was a descendant of Dave, and who was declared the Son of God with power according to the Spirit of holiness, as seen in the resurrection of the Christ, known as Jesus. Romans 1: 1-4
Paul is introducing himself through his relationship with Jesus, with whom he may have only experienced in the Spirit and not directly in the flesh. Paul took very seriously that visitation of Jesus on the road to Damascus. Jesus' glory was fully revealed to him on that road in such a way that he was forever changed.
Although Paul might have seen Jesus, having traveled in Jesus' time and venue, he was, at least, on the edges of the conversations about Jesus, enough that he took on the vendetta of persecution of early Christians. In many ways we are like Paul. We hear of Jesus. We hear other people talk about him, maybe some not favorably.
Some, like Paul, have a spiritual experience with the Christ. I would propose it is actually the hallmark of being introduced to Christ: more than what we hear or what we intellectually know, but rather what we have experienced in His presence. It can be hard to convince others of our experience with Christ, but like Paul, our lifestyles could be the most convincing way to do so.
Paul's turnaround was dramatic! Once on the sidelines (Acts 22:20) then in the fray. Once a persecutor, then a supporter and leader. Has your experience of Christ changed you? Motivated you? Caused you to be either supporter or leader? Our other relationships change us, whether it is being a friend, friend, spouse...every relationship asks something of us.
I once kept a sign in my office: "What are you going to do about what you believe?" Maybe it should have said, "What are you going to do in response to your relationship with Christ?"