Whoever transgresses and does not abide in the doctrine of Christ does not have God. He who abides in the doctrine of Christ has both the Father and the Son. – 2 John 1:9

If we are one with Christ, we should go through the world like princes; we should be like Abraham among his fellows, who claimed no princedom, and wore no crown, yet who could say to the King of Sodom what he had already vowed to God, “I will not take from thee a thread unto a shoe-latchet, and I will not take anything that is thine, lest thou shouldest say, I have made Abram rich.” If you are one with Christ, treat the world in that way. O world, thou canst not bless me! God hath blessed me. Thou canst not curse me! God hath blessed me. Dost thou laugh? Laugh if it pleaseth thee. Dost thou frown? What signifieth it to me? If God has smiled upon me, thou mayest spurn me. If I am one with Christ, I expect that thou shouldest think little of me; for thou didst spurn my Head. Should the body of Christ expect better treatment than the Head received?

If we are one with Christ, we shall remember that to dishonour ourselves is to implicate our Lord. If I dishonour any part of my body, my head feels the shame of it; and since we are the members of Christ, we should be very careful how to behave, lest we should cause Him pain. Men will judge Christ by His people. If I caught sight of a pair of legs very unsteadily walking along the street, I should be inclined to say that they belong to a drunken head. If our walk among men is not such “as becometh the gospel”, what hard thoughts those around us may have of our Saviour! Of course, we know that any ill estimate of Him will be false, for He is all fair, and there is no spot in Him; but still His name and His cause will suffer dishonour. Let us not, then, injure or defile ourselves, lest we should bring reproach upon Him whom we love! ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/2244.cfm