“If He’s gonna be perfect humanity, He’d better have perfect human flesh untainted by sin.”
Who says that a Zygote/embryo is tainted by sin?
The “If This then this” without looking and discussing all alternatives for an explanation is the sort of thinking conspiracy theorists use not serious theologians or critical thinkers.
For this thinking to work Mary must have had a mother untainted by sin and so on and so on!
Mel
In Christian theology two kinds of sin are distinguished, actual personal sin — a baby cannot commit that — and original sin which is an inherited condition. Accordingly, the Church teaches that Mary was free from original sin in order to be the perfect tabernacle of the Lord, as well as that she never committed a personal sin.
Christ could — in terms of ability — have freed also Joachim and Anna from original sin, or to that matter the whole mankind from original sin, but that would have violated the divine justice. That justice required that the perfect sacrifice of Christ be made for sin, rather than sin gratuitously removed from us. Therefore, Christ only did what was necessary for His incarnation. An indefiled tabernacle — Mary — was necessary; a sinless grandmother was not.
Good question.