I don’t contradict myself at all.
Sin comes from within, from the heart as Jesus taught.
It is not transmitted like a disease. It’s inherent in us as humans with a human sinful father.
That is such a strange belief. Sin doesn't come from both parents, but ONLY the father? Makes no sense, since both are equally sinners. However, it seems like a convenient belief for a cult that insists that Mary didn't need to be preserved from all stain of sin to be the Mother of God. No wonder.