That only Paul was the first, not anyone before ?
There is much more behind that statement than most realize:
1 Timothy 1:16
16 αλλα δια τουτο ηλεηθην ινα εν εμοι πρωτω ενδειξηται
Χ̅Ρς
Ι̅Ης την απασαν μακροθυμιαν προς υποτυπωσιν των μελλοντων πιστευειν επ αυτω εις ζωην αιωνιον
1 Timothy 1:16
16 But for this reason I obtained mercy, that in me first
Ι̅Η Χ̅Ρ might demonstrate the totality of long-suffering, for a pattern to those about to believe on him into life eternal.
The pattern contains the entire ministry of Paul, from his conversion at the very beginning, the vision on the road to Damascus, and all the way through Acts, and all of the historical things he records in his letters, and his visions also, (for if they do not apply to us then he was indeed merely boasting for sharing them: and he fully explains that the things he shared in that regard were necessary, and not just boasting), and including also all the pertinent things which he records along the way in his letters to the congregations which he was used by Elohim to form, and to be responsible for. Think long about that: the first event, the vision on the way to Damascus, (after much scripture study in this regard), likely occurred on the 24th day of the first month: same as the vision in Daniel 10, (Dan 10:4, the 24th day of the first month).