Someone asked me this in a YouTube comment.
What an excellent question.
I will answer it in long form in one of the books I'm working on. Here's a short answer by way of scripture references.
From henceforth let no man trouble me: for I bear in my body the marks of the Lord Jesus. (Galatians 6:17)
If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself. (John 7:17)
2 You yourselves are our letter, written on our hearts, to be known and read by all;
3 and you show that you are a letter of Christ, prepared by us, written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of human hearts.
4 Such is the confidence that we have through Christ toward God. (2 Corinthians 3, NRSV)
19 I say unto you, can ye look up to God at that day with a pure heart and clean hands? I say unto you, can you look up, having the image of God engraven upon your countenances?
20 I say unto you, can ye think of being saved when you have yielded yourselves to become subjects to the devil? (Alma 5)
Let thy bowels also be full of charity towards all men, and to the household of faith, and let virtue garnish thy thoughts unceasingly; then shall thy confidence wax strong in the presence of God; and the doctrine of the priesthood shall distil upon thy soul as the dews from heaven. (D&C 121:45)