Incest.

 

Poor King Oedipus!, one of the most mis-interpreted people in history. The story of his mother-carrying, father-killing legend came to be from the ancient system of succession of sacred kings, whereby every previous king was slain by his successor, chosen to be the queen's new bridegroom. The killer was always described as a "son" of the deceased because he was the same god reincarnated in another consort of the same mother-bride.

Such symbolism was practiced in exactly the same manner with christianity; the divine son who is indistinguishable from his father, who impregnated his own mother to beget himself!