Thematic Bible: What preachers should do

Know ye not that they who are employed about the holy things, are fed from the temple? and they who serve at the altar, partake with the altar? So also the Lord hath commanded to those who preach the gospel, that they should live by the gospel.

MY dear children, these things I write to you, that ye should not sin. And if any of us sin, we have an advocate with the Father, Jesus Christ the righteous: and he himself is the propitiatory victim for our sins: and indeed not for ours only, but for the whole world. And hereby we know that we know him, if we keep his commandments. read more.
He that saith, I know him, and keepeth not his commandments, is a liar, and in him the truth is not. But whosoever keepeth his word, verily in him is the love of God perfected: by this we know that we are in him. He who saith that he abideth in him, ought as he walked, even so himself to walk.