I believe that God created angels (Ps. 148:1-6; John 1:1-3; Neh 9:6) who are personal (1 Peter 1:12), spiritual (Heb 1:14), moral (2 Pet 2:4), holy (Gen 1:31), immortal (Luke 20:36) and who have emotions (Luke 2:13) and who have been endowed with limited power (Ps. 103:20) and knowledge (2 Sam 14:20) and are innumerable (Heb 12:22). They are higher than humans, and are lower than Christ (Heb 2:7). They are typically invisible to human sight (2 Kings 6:16-17), but have the ability to appear in human form (Matt 28:5).
I believe that the ministry of the angels is to worship God (Isa 6:3; Rev 5:9; Heb 12:22), to serve as His messengers (Luke 1:11-19), fight against demons (Dan 10:13), execute a limited number of God’s judgments (Rev 8:1-9:21) and to minister to those who belong to God (Ps. 34: 7;Mat 4:11; Heb 1:14).
I believe that Satan, the ruler over all demons, was divinely created to be a holy being (Ezek 28:13-16) and who chose to rebel against God because of his pride to be like God. The result of Satan’s pride is that sin entered the universe (Isa 14:12-15) and Satan was cast out of heaven to earth along with the a third of the angels who followed Satan (Rev 12:3-4). Satan is called the tempter (Gen 3:1-7; 1 Thess 3:5), prince of this world (John 12:31), god of this age (2 Cor. 4:4), and the accuser of the saints (Rev. 12:10). He is leader of an army of evil spirits or demons (Matt. 12:24).
I believe that the angels who followed Satan are called demons or unclean spirits (Luke 8:29), the Devil’s angels (Matt. 25:41), evil spirits (Luke 7:21), and spiritual forces of wickedness (Eph. 6:12). They seek to frustrate the work of God (Eph 6:12; Rev 12:7) by manifesting physical pain and suffering (Luke 13:11-16), inhabiting unbelievers (Matt 9:32-33; 1 John 5:18), advancing false doctrines (1 Tim. 4:1), deception, accusation, and temptation of believers (Jas. 4:7; 1 Pet. 5:8). Demons fail in their actions in the believer who is fully equipped with the full armor of God (Eph 6:10-20).