Hebrews 9:15

Brethren, this is the critical point to understand in the entire plan of God. The original promise was made directly to Jesus Christ. He is the true Heir, the one Seed, the One who brings the whole plan together.

So here is the big thunderbolt. The covenant made to Abraham and the New Covenant in Christ are one continuous promise.

Christ did not come to change the promise. He came to confirm it. He was the first to receive that eternal inheritance.

Hebrews 9:11-15

This is telling us here that He did all of this for us. He came down as the greatest Priest of all to make sure that all of these things were done. He lived without sin, and He gave His life to purge us, to purge our consciences of guilt, to help us in every way so that we, the called, may receive the promises of the eternal inheritance that God has offered to us.