Ministering angels are an indispensable part of the Gospel of Jesus Christ. That is why those keys were restored so early on in this Dispensation and are so widely disseminated into the LDS Church membership (see JSH 14:1). There is a system by which men learn the mysteries of heaven and are saved. That system is set out in Alma 9:7 : first, angels are sent to prepare men and women; second, they are allowed to behold the Lord’s glory; third, they converse with the Lord, at which point they are taught the things that have been prepared from the foundation of the earth for their salvation. All of this is driven by the man or woman’s faith, repentance, and holy works. This is in keeping with Joseph Smith’s revelation about those chosen to become a member of the Church of the Firstborn. They are chosen by the holy angels, to whom the keys of this power belong (see T&C 74:8). If this isn’t happening, then faith does not exist on the earth any longer (see Moroni 7:7).1 Angels minister to “chosen vessels” or mortal messengers, as the Three Nephites did with Mormon and Moroni (see Mormon 4:2). Then these vessels testify and bear testimony so that the way is prepared that the residue of men may have faith in Christ (Moroni 7:6). These three visited with Mormon, but the people to whom Mormon ministered didn’t see them. They ministered to Moroni, and those to whom Moroni ministered didn’t see them. The chosen vessels also become as ministering angels.2 Heaven’s “chosen vessels” may seem most unlikely. In the cases of Alma the Younger and Saul of Tarsus, they were wicked when they were chosen. Yet both would later become ministering servants who preached righteousness to the residue of men.3 Many people have received ministering angels. Men, women, and children have, can, and do receive angelic ministers (see Alma 16:26). When they minister to a man or a woman, it is to enable them — the ones being ministered to — to testify and help others to likewise have faith in Christ.4 Angels minister to those with faith, who are supposed to then preach salvation to others.5See also ANGEL.
1 “Angels,” March 6, 2010, blog post.
2 “The Holy Order,” Oct. 29, 2017, 16, paper.
3 “The Holy Order,” Oct. 29, 2017, 16n62., paper.
4 “The Holy Order,” Oct. 29, 2017, 16n63., paper.
5 “The Holy Order,” Oct. 29, 2017, 16., paper.