Only the apostles were in a position to know for sure if Jesus was resurrected and appeared to them. For anyone else it must be taken on faith. And these apostles demonstrated all to eagerly ...
It is the height of arrogance to dismiss the the desciples of Kali, of Mitra, of Apollonius, etc. It is equally arrogant, or ignorant, to similarly dismiss the disciples of Gnosticism.
Sorry, keith63, but you know absolutely nothing about what, if anything, the apostles migh or might not have done other than what you think you know through reading redacted, 2nd-hand accounts, crafted decades after the fact, and carefully filtered by Church censorship. The relative success of Christianity over competing fantasies is due, more than anything else, to Constantine.