A lot of college students are taught that many of the themes in the life of Jesus are merely echoes of ancient “mystery religions,” in which there are stories about gods dying and rising, and rituals of baptism and Communion.
Though this was a very popular argument at the beginning of the twentieth century, it generally died off because it was so discredited. For one thing, given the timing involved, if borrowing is going to be entertained, it should be done so as to indicate that the mystery religions borrowed from Christianity, not vice versa.
The mystery religions were do-your-own-thing religions that freely borrowed ideas from various places. The Jews, however, carefully guarded their beliefs from outside influences. They saw themselves as a separate people and strongly resisted pagan ideas and rituals.
Senior Swedish scholar T. N. D. Mettinger said that the consensus among modern scholars — nearly universal — is that there were no dying and rising gods that preceded Christianity.
Even if there might have been, these stories revolved around the natural life cycle of death and rebirth. Crops die in the fall and come to life in the spring. People expressed the wonder of this ongoing phenomenon through mythological stories. These stories were cast in a legendary form. They depicted events that happened “once upon a time.”
Contrast that with the depiction of Jesus Christ in the Gospels. They talk about someone who actually lived in the same historical time frame, and they name names: for example, Jesus was crucified under Pontius Pilate (see Mark 15:1–15) when Caiaphas was the high priest (see Matthew 26:57), and Simon, the father of Alexander and Rufus, carried Jesus’ cross (see Mark 15:21). That’s concrete historical information. It has nothing in common with stories about what supposedly happened “once upon a time.”
Christianity has nothing to do with life cycles or the harvest. It has to do with a very Jewish belief — which is absent from the mystery religions — about the resurrection of the dead and about life eternal and reconciliation with God.
As for the suggestion that the New Testament doctrines of baptism or Communion come from mystery religions, that’s completely false. For one thing, the evidence for these supposed parallels comes after the second century, so the mystery religions would have borrowed from Christianity, not the other way around. And when carefully inspected, the similarities vanish. For instance, to get to a higher level in the Mithra cult, followers had to stand under a bull while it was slain, so they could be bathed in its blood and guts. Then they’d join the others in eating the bull. Now, to suggest that Jews would find anything attractive about this and want to model baptism and Communion after this barbaric practice is extremely implausible, which is why most scholars don’t go for it.
Source: Bible Gateway