How does Christ become our propitiation?
Christ becomes our propitiation through faith in His blood, not by His life or exemplary miracle working. God set Him forth as propitiation, and through faith in His blood He declares His righteousness for the remission of sins that are passed through God's forbearance, so that He is just and fair toward the one who believes.
Les explains that "propitiation" is a great big word people stumble over, but it is the most inclusive one word in the New Testament. Christ becomes our propitiation by faith—faith in His blood, not His life or His three years of exemplary miracle working. Through faith in His blood He can declare His righteousness, not ours, for the remission of sins that are passed through the forbearance of God. Verse 26 shows He is just and fair, and the one who believes is the one to whom this applies. Believing is faith, and faith is believing; you can't escape it.
Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;