Paul did not have a horse. That is a later embellishment, probably by some medieval artist. But it might clarify to note that the historical Jesus in his New Testament mission to Israel choose only Jews, symbolically twelve to represent the twelve tribes. Paul himself in his letters says he had a revelation from Christ and had seen the risen Christ, while Luke in Acts has three versions of the encounter, in one of which Paul asks his vision to identify himself, when the risen Christ does so, saying I am Jesus whom you are persecuting. There is no mention here of anyone chosen, no matter how chosen, as priests. The only New testament text that speaks of Christ as a priest is Hebrews in developing its Platonic theology of sacrifice as the instrument of our deliverance from this world of change and decay to the changeless realm of the Sabbath rest in the new Jerusalem. Before Hebrews, ca 100, no priests at all, except for the temple priests, the Saducees.