Where did you get that?
The reasoning goes as follows. We know from Scripture that Jesus died for our sins and that we are all sinners by virtue of our first parents' sin.
Romans 5:12This defect of original sin has been inherited by all mankind, although more in a spiritual sense than a material sense. Therefore, we could not have descended from various parents. Otherwise, some of us would be tainted by original sin while others wouldn't.Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all men