D&C 50:13-22

13Wherefore, I the Lord ask you this question—unto what were ye ordained?

14To preach my gospel by the Spirit, even the Comforter which was sent forth to teach the truth.

15And then received ye spirits which ye could not understand, and received them to be of God; and in this are ye justified?

16Behold ye shall answer this question yourselves; nevertheless, I will be merciful unto you; he that is weak among you hereafter shall be made strong.

17Verily I say unto you, he that is ordained of me and sent forth to preach the word of truth by the Comforter, in the Spirit of truth, doth he preach it by the Spirit of truth or some other way?

18And if it be by some other way it is not of God.

19And again, he that receiveth the word of truth, doth he receive it by the Spirit of truth or some other way?

20If it be some other way it is not of God.

21Therefore, why is it that ye cannot understand and know, that he that receiveth the word by the Spirit of truth receiveth it as it is preached by the Spirit of truth?

22Wherefore, he that preacheth and he that receiveth, understand one another, and both are edified and rejoice together.