“He that saith he abideth in Him ought himself also so to walk, even as He walked.”- 1John 2:6

He that saith he abideth in Him: “-that is exactly what every Christian does say. He cannot be a Christian unless this be true of him, and be cannot fully enjoy his religion unless he assuredly knows that he is in Christ, and can boldly say as much. We must be in Christ, and abidingly in Christ, or else we are not saved in the Lord. It is our union with the Christ that makes us Christians: by union with Him as our life we truly live, live in the favour of God. We are in Christ, dear brethren, as the manslayer was in the city of refuge: I hope that we can say we abide in Him as our sanctuary and shelter. We have fled for refuge to Him who is the hope set before us in the gospel; even as David and his men sheltered themselves in the caves of En-gedi, so we hide ourselves in Christ. We each one sing, and our heart goes with the words-

“Rock of ages, cleft for me,
Let me hide myself in Thee.”

We have entered into Christ as into the shadow of a great rock in a weary land; as a guest into a banquet-hall, as returning travellers into their home. And now we abide-in Christ in this sense, that we are joined to Him : as the stone is in the wall; as the wave is in the sea; as the branch is in the vine; so are we in Christ… Today we remain in Christ, and hope for ever to remain in Him, as our Head. Ours is no transient union; while He lives as our Head we shall remain His members. We are nothing apart from Him. As a finger is nothing without the head, as the whole body is nothing without the head, so should we be nothing without our Lord Jesus Christ. But we are in Him vitally, and therefore we dare ask the question, “Who shall separate us from the love of God which is in Christ Jesus our Lord?” ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1732.cfm