Michael the Archangel

Concise Bible Dictionary:

In Daniel he is called “one of the chief princes,” “your prince,” “the great prince which standeth for the children of thy people.” He went to the assistance of one (probably an angel) who had been sent with a message to Daniel, but who had been detained twenty-one days by the prince of the kingdom of Persia (doubtless Satan, or one of Satan’s angels, who was acting for the kingdom of Persia, as Michael was prince for the children of Israel) Daniel 10:13,2113But the prince of the kingdom of Persia withstood me one and twenty days: but, lo, Michael, one of the chief princes, came to help me; and I remained there with the kings of Persia. (Daniel 10:13)
21But I will show thee that which is noted in the scripture of truth: and there is none that holdeth with me in these things, but Michael your prince. (Daniel 10:21) and Daniel 12:11And at that time shall Michael stand up, the great prince which standeth for the children of thy people: and there shall be a time of trouble, such as never was since there was a nation even to that same time: and at that time thy people shall be delivered, every one that shall be found written in the book. (Daniel 12:1). It is also said of Michael that when he contended with Satan about the body of Moses, he durst not bring a railing accusation against him, but said, “The Lord rebuke thee.” Michael and his angels will however fight with Satan and his angels, and will prevail, and Satan will be cast out of that portion of heaven to which he now has access (Jude 99Yet Michael the archangel, when contending with the devil he disputed about the body of Moses, durst not bring against him a railing accusation, but said, The Lord rebuke thee. (Jude 9); Rev. 12:77And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels, (Revelation 12:7); compare Job 1:66Now there was a day when the sons of God came to present themselves before the Lord, and Satan came also among them. (Job 1:6); Job 2:11Again there was a day when the sons of God came to present themselves before the Lord, and Satan came also among them to present himself before the Lord. (Job 2:1)). These are illustrations of the conflict of good and evil spirits in the unseen universe.