W, two principles are the basis of faith. First, you choose what you like, and second, you act as if it is true. Mr. Paul acknowledges it in his statement that faith is the substance of things hoped for, evidence of things not seen.

He makes a similar statement that if Christ isn't risen, preaching is in vain as is faith. 

He chooses the concept of a risen Christ. And he affirms it is based on hope and unseen things. He recognize it might not be true by acceding "hope" as operative in the first instance and "if" in the second. But he acts as if it is true with his post-tormentor lifetime investment. 

No one knows for sure if the tomb was empty, why, and where the body may have gone. Not you or me, W. The gospels have differing accounts as does Mr. Paul. Eye witnesses are unreliable even now where we have cameras and instant deposition.

The theory that Paul ever saw Jesus is myth. But you believe it and act as if it is true.

Believe what you like, W. Mr. Paul did.