When Alma declared that he wanted to be an angel, he probably was not thinking about a random angel in the abstract. If you remember, Alma had first-hand experience with an angel. This angel cried repentance and spoke with the voice of thunder. The angel’s power knocked everybody down, and caused Alma to be physically afflicted for days. Alma was likely thinking that this was the kind of angel he wanted to be. An angel that had the power to bring about mighty repentance.
On an interesting note, Alma had been serving for the last eight years as the high priest of the temple. In the Israelite temple, angels appeared to God’s servants, such as Isaiah and Zacharias. Sometimes the angel was none other than the Lord himself. The angel of the Lord was often a name or euphemism for God himself appearing at the temple in the Holy of Holies. We do not know if Alma ever had angelic experiences in his service in the temple. Interestingly, Alma was not in the temple either time that the angel appeared to him. Alma knew that it was possible for an angel to appear outside of sacred precincts. His angelic experiences likely helped Alma recognize what it may have meant if he could have taught with angelic power: “And that I could have the wish of mine heart” (29:1).
What would you wish for if you could have the wish of your heart? We know what Alma’s heart was set on: wishing that he could bring repentance to every people. He was not some kind of an aristocratic, exclusivist leader, but rather wanted to embrace all people inclusively. That was unusual in the Israelite tradition because the high priest typically felt so strongly the need to protect his own purity. Jesus’ eating with the ordinary people, the sinners, the publicans, and the tax collectors, was concerning to people because that would have defiled him, in their minds. Even more so, the high priest needed to keep himself pure, but Alma did not approach his priesthood responsibility that way at all. He went out, even to do battle with Amlici and to call the unholy people in Ammonihah to repentance.
Book of Mormon Central, “Why Was Alma’s Wish Sinful? (Alma 29:3),” KnoWhy 137 (July 6, 2016).
Book of Mormon Central, “Why Did Alma Wish to Speak “with the Trump of God”? (Alma 29:1),” KnoWhy 136 (July 5, 2016).