Paint rags amid the linens…
I don’t know about you but I know in our home if after my wife has washed and spun the sheets, pillowcases and hand towels, hung them to outdoors to finish drying, brought them in again with that fresh outdoors smell of cleanness, folded them and stacked them neatly, she would not appreciate it if I “added” to the pile my several oily or paint stained rags from the garage! My “addition” would certainly not be seen as an “addition” at all! Immediately the rags would need to be removed and much off the laundry would need to be washed again. My “addition” would prove only to have been a “subtraction.”
Scripture informs us that God is Holy (Lev. 11:44; 1 Pet. 11:16; Rev. 15:4). No unholy thing may stand in His Presence, and fallen man has become an unholy thing! The prophet Isaiah summarizes: “…all our righteous acts are like filthy rags…” (Isa. 64:6a). If I try to add my works to God’s grace it is like adding oily rags amid the linens.
Jesus is the only qualified God-man, the only Righteous One capable of being our Mediator. He satisfied fully the sin debt (propitiation) owed to God, and bought us back (redemption) by the purity (efficacy) of His sacrifice. Because He was sinless He owed nothing on behalf of Himself and was thereby qualified to die on behalf all who trust Him.
But if we try to add to that by trusting in our own goodness, by trying to “top up” the work of God, all we do is to mix impurity to purity. When a thing is already perfect nothing more can be added to it.
This is where Pastor Andrew’s illustration from algebra comes in. Human effort added to grace does not add to it at all, but instead only subtracts from it. Like adding a negative number to a value the whole is not enhanced but is diminished: e.g. 5 + -3 = 2.
Jesus paid 100 % of each believer’s redemption. He has paid 100% of my redemption. In this transaction His righteousness is given to me. In the eyes of the Father I, a believer, stand justified — “just-as-if-I’d” never sinned. All I have to offer is unrighteousness. My job is simply to understand this is true, keep my filthy hands off the perfect grace of God, and trust fully now in our Lord Jesus Christ!