It's about how one sees life. Saul of Tarsus fought Truth with a religious zeal.
Then, there was that incident on the road to Damascus.
When his eyes were finally opened, Saul, now Paul, saw with a different light from the Light within him. As a spiritual man for the first time, he no longer saw the world as a natural man, even a religious natural man.
The rest is history, or His story,
DF
Saul, who wrote 1/2 the new testament, who never met Jesus prior to his crucifixion, and only interaction allegedly occurred on a read in the middle of nowhere.