But when it pleased God, Who appointed me out from my mother’s womb and called me through His grace, to reveal His Son in me, in order that I should evangelize Him among the nations, I did not immediately confer with flesh and blood (Galatians 1:15–16).
Although Paul had a unique experience with the resurrected Christ on the Damascus road, it was not this experience that saved him. Grace saved Saul, just as it saves us today. Grace is God’s attitude whereby He gives a benefit without consideration of merit. Even though Saul saw and heard Christ, he still expressed faith in who Christ was, including His death for our sins and His resurrection three days later.
As a Jew, Paul was separated unto God from his birth. The Son of God was revealed to him when it pleased God the Father, Who desired to place Paul as the apostle to the Gentiles (1 Corinthians 1:1).
The gospel Paul taught was not given to him by men. After his experience on the Damascus road, he spent three years in Arabia learning from the resurrected Christ. During this time, Christ gave Paul all the instructions for the dispensation we live in so he could dispense them to the nations for everyone who believes in Christ’s death on behalf of our sins and resurrection three days later (1 Corinthians 15:3–4).