Here's one version of the religious answer.
God made man in his image but then lost interest when he made Eve from Adam's rib, and she contained the mutated "sin" gene, which she and Adam then proliferated.
A lot later God saw that this was not good so he impregnated Mary who duly produced Jesus. Unfortunately Mary had the sin gene so this was passed on to Jesus who became gay (which was a sin in those days) so they crucified him. This was supposed to wash away all our sins, but his genetics being a bit rusty after all these years since his original creation, God got it wrong and the sin gene survives to this day.
We await the next Messiah.