Yes, it's true. Christianity borrowed extensively from prior religions.
This fact is NOT something your priest wants you to know.
We don't know exactly when these dying-reborn Gods began – they date back thousands of years, basically fading into prehistory. We do know early Christian writers recognized that Jesus came at the end of a long history of Gods who died and were reborn. According to apologist Origen, the list of death-defying gods includes:
"the Odrysian Orpheus, and the Thessalian Protesilaus, and the Taenarian Hercules, and Theseus also."
But, says Origin, the stories of these other dying-reborn Gods need not be believed,
"For each might, had he wished, have secretly withdrawn himself from the sight of men, and returned again. These older stories are myths, but the story of Jesus' death and resurrection should be believed."
So the previous gods simply hid themselves, pretending to be dead, then suddenly reappeared as resurrected . . . like peek-a-boo on steroids. But Jesus didn’t do that. Really. No, really!
Justin Martyr an early Christian apologist claimed that Satan tried to usurp Jesus by coming centuries before him to "seed" many religions with stories of virgin births, death and resurrection, etc., thus diluting Jesus' message. But, according to Justin Martyr, they are false and Jesus is real. This is sort of like the Fundamentalists of today saying that God layered fossil evidence in the earth to test our faith in him. LOL, now THAT’S a good one!
Religion is big business; they'll say anything to keep it going.