“the Lamb who was slain from the creation of the world” Revelation 13:8
To be the Lamb required a perfect human. A human counterpart to lamb needed perfection in not sinning. That meant proof of perfection. This proof required temptation. God the one true God cannot be tempted. So the lamb needed to be human, and this was true before the world began, and set the course of sacred history. A human as lamb needed to not be God by nature, because God by nature cannot be tempted. The word was divine by nature. So it would become flesh, then this lamb, the Christ, would be flesh and only have divinity conferred by the Father, who is God by nature.
