For Moses describeth the righteousness which is of the law, That the man which doeth those things shall live by them. – Romans 10:5

If you wish to be saved by the law you must do its commands and you shall live. The law is written in the ten commandments; you know them; and if you desire to live by them you must keep them. It will not suffice for you to learn those commands by heart, or to write them up in your churches, or to read them over and say, “Lord, have mercy upon us, and incline our hearts to keep this law”: all that may be well enough, but it is not to the point. If you are to be saved by the commandments you must do them: that is clear. Moses does not allow any person to dream that under the law he can be saved in any other way than by perfect obedience thereto. “For not the hearers of the law are just before God, but the doers of the law shall be justified.” Whatever it is that God has commanded, you must do; whatever He forbids, you must avoid; for by such obedience alone can you live.

Christ’s fullness is meant for our emptiness; Christ’s righteousness is meant for our sin; salvation is for the lost. When you and I are no longer sinners, Christ is no longer our Savior; when you and I no more need Him, then we shall not have Him. Our need is our warrant, and if that be gone, all is gone. Jesus did not bleed and die to be a superfluity to us: He came to meet a grim necessity. As long as we are nothing Christ is our all in all; we may be sure of that, and that is just the gospel in a nutshell…Jesus came into the world to save real sinners, not sham sinners; for He is a real, and not a pretended Savior. He saves those who are always confessors of sin, always needy in themselves, and therefore always glad of Him. Even in their best estate the saved ones need their Lord: even if we walk in the light as God is in the light, and have fellowship with Him, we still sin, and still the blood of Jesus Christ, His Son, cleanseth us from all sin. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1700.cfm