The Holy Ghost Reveals That Jesus Is the Christ

1 Corinthians 12:3

3 Wherefore I give you to understand, that no man speaking by the Spirit of God calleth Jesus accursed: and that no man can say that Jesus is the Lord, but by the Holy Ghost.

President Harold B. Lee said:

“Not many have seen the Savior face to face here in mortality, but there is no one of us who has been blessed to receive the gift of the Holy Ghost after baptism but that may have a perfect assurance of His existence as though we had seen. Indeed, if we have faith in the reality of His existence even though we have not seen, as the Master implied in His statement to Thomas, even greater is the blessing to those who ‘have not seen, and yet have believed’ (John 20:29), for ‘we walk by faith, not sight’ (2 Corinthians 5:7). Although not seeing, yet believing, we rejoice with joy unspeakable in receiving the end of our faith, even the salvation of our souls [see 1 Peter 1:8–9].

“The testimony of Jesus is the spirit of prophecy [see Revelation 19:10] and comes only by the power of the Holy Ghost, for ‘no man can say that Jesus is the Lord, but by the Holy Ghost’ (1 Corinthians 12:3). If we have lived worthy of such a testimony, we may have ‘a more sure word of prophecy’ (2 Peter 1:19) by asking God, ‘nothing doubting,’ and ‘by the power of the Holy Ghost, [we] may know the truth of all things’ (Moroni 10:5).”

(Stand Ye in Holy Places [1974], 32.)