“Your righteousness is of Me, saith the Lord.” – Isaiah 54:17

What is your righteousness? O, I am as good as my neighbors. Go along with you; you are not my comrade. What is your righteousness? Well, I am rather better than my neighbors, for I go to chapel regularly. Off with you, sir; you do not know the watchword. And you next; what is your righteousness? I have been baptized, and am a member of the church. Yes, and so you may be; and if that is your hope, you are in the gall of bitterness. Now, you next; what is your hope? O, I do all I can, and Christ makes up the rest. Rubbish! You are a Babylonian, you are no Israelite: Christ is no make-weight-away with you. Here comes the last. What is your righteousness? My righteousness is filthy rags, except one righteousness which I have, which Christ wrought out for me on Calvary, imputed to me by God Himself, which makes me pure and spotless as an angel. Ah, brother, you and I are fellow-soldiers: I have found you out; that is the watchword. “Your righteousness is of Me, saith the Lord.” I do not ask whether you are Churchmen, or whether you are Methodists, or Independents, or Baptists, if you do but know this watchword-“Your righteousness is of Me, saith the Lord.” I can forgive all those other minor things, if you can sing-

“Jesus, Thy blood and righteousness,
My beauty are, my glorious dress.”

Tell me you have got any other trust, and I will have nothing to do with you. Tell me you can work out your own salvation, and I will not acknowledge you for a brother. But if you tell me that from first to last you rely on Jesus, then I acknowledge you as a fellow-soldier; and I am glad to see you wherever I meet you. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2908.cfm