"The suffering of our Mediator does not date from the end of His stay on earth . . . . The blood of the Savior's circumsicion is as much atonning blood for us as is the blood shed on Galgotha. His entire life was a continual suffering."
Geerhasdus Vos (quoted in O Come, O Come Emmanuel, Jonathan Gibson).
We are saved because Jesus fulfilled all the law; he perfectly obeyed God's law on our behalf. We are saved because Jesus suffered the just wrath of God and died paying the penalty of the law on our behalf.
Christmas is the beginning of our salvation. On this first day of a new year, know that you are one with a savior who has flesh and blood just like you and never failed to do all that was required of him.
"For God has done what the law, weakened by the flesh could not do. By sending his own Son in the likenss of sinful flesh and as a sin offering, he condemmed sin in the flesh in order that the righteous requirement of the law might be fulfilled in us."
Romans 8:3,4
"I have been crucified with Christ. It is no longer I who lives, but Christ who live in me. And the life I now live in the flesh, I live by faith in the son of God, who loved me and gave himself for me. Gal. 2:20
https://www.ligonier.org/.../active-and-passive-obedience...