I have been asked to research to what extent is the doctrine of the divinity of Christ necessary for an understanding of Redemption. Any ideas?
My first thought is that a debt to an Eternal God (to whom all things, including debts, are eternal) can only be paid by a Victim that is also Eternal.
This is a good, but very complex question. You might want to check out St. Anselm’s “*Cur Deus Homo?” *(Why the God-Man?)
I think Fidelis is on the right track. Keep that in mind check into Dr. Scott Hahn’s “covenant theology” and compare it with Heb. 9:16. You’ll hopefully see that because God swore a covenant with us it required Him to scarifice Himself.
Check out Chapter 2 of the CCC, mainly article 3, section III. It addresses the heresies that result when one denies any aspect of the Incarnation. Nestorianism would be the one you’ll probably want to look at.