A title that means “accuser,” “opponent,” and “adversary”; hence, once he fell, Lucifer became — or in other words, was called — Satan because he accuses others and opposes the Father (see Revelation 4:3; 8:6). The Lord rebuked Peter and called him Satan because he was wrong in opposing the Father’s will for Him, and Peter understood and repented. There are those who have been Satan, accusing one another, wounding hearts, and causing jarring, contention, and strife by their accusations.1 Satan was (and is) an angel. He is described as an angel of God who was in authority in the presence of God (T&C 69:6) and was cast down (T&C 157:7). Such a being does not look vile. Visually, he may appear to have light and glory. Although a liar, he uses his appearance as a pretense to be an angel of light. Moses was able to discern between Satan and an actual messenger from God, but that had nothing to do with the appearance of Satan. It was because of the content of the message. Moses distinguished between his message and the Lord’s. The Lord’s was a message of glory, which is intelligence, or in other words, light and truth. Satan’s message takes one into a dark and dreary waste.2See also ACCUSE; LUCIFER.
1 T&C 158:9 Answer to Prayer for Covenant.
2 Preserving the Restoration, 76.