Stephen died of heart attack. His soul was received in heaven. He was astonished to find himself as young as he had been in his young adult age. He looked around and there were thousands of young and naked people. His eyes searched to find someone familiar and suddenly he noticed Adam and Eve.
How did Stephen recognize them?
Adam and Eve were the only people without navel. As they were not born out of a mother, they never had umbilical cords and thus never had navels.