But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach; that if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised Him from the dead, thou shalt be saved. – Romans 10:8,9

The gospel speaking for itself declares, this word of life by faith in the risen Christ to be near us, that is, to be accessible to us. As your next-door neighbor’s house is not hard to get at, so neither is salvation by the gospel. It is nigh you; it is nigh you now: it will never be nigher than it is at this moment. You may now believe in Christ and live eternally. Difficulty there is none: only believe and thou art saved. It is not a mystical, obscure thing; it is near and familiar. Believe in Christ as you would believe in your friend: believe that He died for sinners, and trust in Him for salvation. If God has made you feel yourself a sinner, then Christ is such a Savior as you need, and you may have Him at once: the only difficulty lies in the way being so easy that you can hardly think it can be so. Have done with doings, and feelings, and trust yourself with Christ. “The word is nigh thee.” It is simple; indeed, so simple that people try to obscure it in order to understand it. It is such milk for babes that I have known people refuse such plain truth because they were not willing to be treated like little children. Just as I lean all my weight upon this rail so do I lean my soul wholly upon Christ. If what Christ has done will not save a sinner I am damned; for I have nothing else to depend upon; but if it will save, and sure I am that it will, I am saved as surely as Christ has risen from the dead. This is the substance of the matter-Christ saves, and we trust. This is what that word of faith says, even the gospel which we preach. I am afraid we say a great deal at times which rather lumbers and cumbers the gospel than makes it clear. Perhaps I am doing the same this morning, but I do not mean to do it. I mean to let it stand out simply before you, that the incarnation, the life, the death, and the resurrection of Christ are the one foundation upon which we must depend for eternal salvation, and upon that alone; and if we do so depend we shall most assuredly be saved. ~ C.H. Spurgeon

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