The Mechanism of Sin

Arthur Custance's argument about the mechanism by which sin may be genetically transmitted is a very reasonable one, (at least to my way of thinking), and helps us to understand why the blood line of the promise through legitimate heirs from Eve down through Mary is uninterrupted, while only the Kingly promise (not the blood line -- see Jer. 22:30, 36:30) is preserved from Abraham to Joseph.

The conception of Jesus in the womb of Mary by the Holy Spirit interrupted the chain of genetic links beginning with the fall, allowing a descendant of Adam to be born into the world free from original sin. The perfect obedience of Jesus during His life on earth also was necessary to assure that He reached the cross as a fully qualified sin-offering.

Scripture emphasizes the humanity of the Messiah as fully as it does His Deity. The Old Testament is replete with references to the Messiah as the "root out of dry ground," "the seed of David," "the suffering servant of the LORD," and so on.