The idea of resurrection is not unique to Christianity. It is found across time, cultures, and all sorts of religions.
From a psychological point of view, it probably took root in our ancestors’ psyche as a defense against the meaninglessness of their short and brutal lives.
From evil’s point of view, it was (and still is) used as a bludgeon to keep the masses in line and keep their sin-offerings rolling in.
From God’s point of view, resurrection is simply what a parent gives to their hungry, empty children. (Jesus in Matthew 7:9)
The empty tomb only begins to make sense to those willing to admit their own emptiness.