1 John 2:2

The One who is our Advocate on high is also "the propitiation for our sins." This fact brings us back to the rock foundation upon which everything rests. His propitiatory sacrifice has met every claim of God against us, and He takes up His advocacy with the Father on that righteous basis. His propitiation has settled for us as sinners the eternal questions our sins have raised. His advocacy now settles the family questions that come up when we, as children of God, sin.

Writers have often pointed out that the word translated propitiation in this passage really means "mercy-seat," or propitiatory — that is, the place where propitiation was made. This is easy to see if we remember what Aaron did on the great day of atonement. God told him to carry the blood of the sin-offering into the holiest place of all. There he sprinkled it on the mercy-seat, and in front of it too. Now it was the blood so sprinkled that made propitiation, as far as the picture goes. Aaron sprinkled it there for the eye of God, and it met all His claims on His people because of their sins. … In the tabernacle the mercy-seat was hidden behind the veil. In the gospel Christ, as the mercy-seat, is set out publicly before everyone. So whoever accepts God's testimony to the power of His precious blood may come near with confidence.

The words some want to leave out are necessarily implied; for what else does "not for ours only" do but imply them? Had it said, "not for us only," it would have been entirely different; but "not for ours only" must imply: then for the sins of others also.

Christ is a propitiation in a general way for the whole world, but only "for our sins." There is a marked distinction when he speaks of the whole world. So it is wrong to put in "the sins" when the world is in question… If the Lord had been the propitiation for the sins of the whole world, then the whole world would receive the fruit of it and go to heaven.

Being the Godward side of His death, the widest possible circle is in view — "the whole world." When the substitutionary side is stated, only believers are in view: it is "our offences," or "the sins of many." Only believers stand in the realised benefits of the death of Christ. Yet God needs to be propitiated about every sin men have ever committed, and about the whole great outrage sin has done. In the death of Christ He has been propitiated. Because of this He can offer forgiveness to men freely, without compromising one feature of His nature and character in the smallest degree. … God is not against man but for him. What righteousness demanded, love supplied. God Himself provided the propitiation: His own Son, who was God, became it.

The evangelist cannot go and tell every creature that Christ died as his substitute. But he can tell him that He died as a propitiation. Then, when through grace the soul believes on the Lord Jesus Christ, he can learn the further calming truth: He died as a substitute, and bore all his sins in His own body on the tree.