What is the church? And what can we liken it to in Genesis 15?
"And he (Abram) believed in Yahweh, and he reckoned it to him as righteousness."
God has made all the promises. God has done all the heavy lifting. Literally, He has lifted all the heavy things. Your Sin. Your death. Your punishment. Your obligation to worship Him as God. Your righteous life which you should lead before a loving Creator Father God. Your obedience. All of these things were lifted up upon a wooden cross. All of these things were bled for. All of these things were despised and cut off. All of these things bore the full wrath of the Justice of God.
They are paid for. It is finished.
The church are those who believe this. The church are those who are affected by this and effected by this and changed by this belief. The church are those who attempt to live according to this belief.
You see, i must say 'attempt' for on this side of death, none but Jesus did it completely or correctly but because he did 'it is credited to (us) as (if it were our) righteousness.'