For the law was given by Moses, but grace and truth came by Jesus Christ. – John 1:17
Our Lord Jesus Christ is said to be grace and truth in this sense, that He truthfully deals with matters of fact in the case of our salvation. I know the notion of the world is that the salvation of Christ is a pretty dream, a handsome piece of sentiment. But there is nothing dreamy, about it: it is no fiction; it is fact upon fact. The Lord Jesus Christ does not gloss over or conceal the condition of man in his salvation; He finds man condemned and takes him as condemned in the very worst sense, condemned of a capital offense; and as man’s substitute He endures the capital penalty, and dies in the sinner’s stead. The Lord Jesus views the sinner as depraved, yea, as dead in trespasses and sins, and He quickens him by His resurrection life. He does not wink at the result of the fall and of actual sin; but He comes to the dead sinner and quickens him; He comes to the diseased heart and heals it. To me the gospel is a wonderful embodiment of omnipotent wisdom and truth. If God could be unjust to save us, He could also be changeable, and cast us away. If there was anything rotten in the state of our salvation, we should fear that it would fail us at last. But our foundation is sure, for the Lord has excavated down to the rock; He has taken away every bit of mere sentiment and sham, and His salvation is real throughout.
But it means more than that. The Lord deals with us in the way of grace, and that grace encourages a great many hopes, but those hopes are all realized, for He deals with us in truth. Our necessities demands great things, and grace actually supplies those great things. O brothers in the salvation of Jesus there is a truth of grace unrivaled! There is a deep verity, a substantiality, an inward soul-satisfaction in the sacrifice of Christ, which makes us feel it is a full atonement-a fountain of “grace and truth.” ~ C.H. Spurgeon