What biblical evidence supports the teaching that Michael is another name for Jesus?
The name Michael is used five times in the Bible to designate a celestial being (Dan. 10:13, 21; 12:1; Jude 9; Rev. 12:7). He is nowhere explicitly identified with Jesus, but some Christian writers have equated the two by carefully comparing the role played by Michael with that of Jesus. Any comparisons yield not only similarities but also dissimilarities, and both should be taken into account. We'll start with the passages in which Michael is mentioned and then broaden the horizon to include several passages that are conceptually related to His person and experience.
1. He seems to be an angel: Michael is identified as "one of the chief princes" (Dan. 10:13), "your prince" (verse 21), "the great prince" (Dan. 12:1), and "the archangel" (Jude 9). "Archangel" implies that He is the prince of the angels, suggesting that Michael cannot be another name for Jesus because He is divine and angels are created beings.
Part of the problem is that the noun "angel" is taken to designate a creature, while in the Bible it designates a function. In other words, an "angel" is a being who functions as a "messenger" of God. In most cases they are created beings, but there is an exception.
In the Old Testament there are several references to the "angel [messenger] of the Lord" in which He is equated with God (e.g., Ex. 3:2, 4; Judges 6:12, 14). It is not that the Messenger is identified with the One who sent Him as His representative, but rather that the Sender functions at the same time as the Messenger. Many Christians have identified the Angel of the Lord as the preincarnate Christ. This Christological interpretation seems to be biblically valid.
2. He is leader of the angels: The phrase "one of the chief princes" (Dan. 10:13) could give the impression that He is one among many princes. But according to Revelation 12:7, Michael is the supreme leader of the heavenly angels, or "the great prince." When necessary, He personally assists angels in their assigned tasks (Dan. 10:13), yet the angelic hosts are under His command (Rev. 12:7). He is indeed the "archangel" (Jude 9). This title is mentioned in one other place in the Bible: 1 Thesselonians 4:16, in the context of the second coming of Christ. He returns "with the voice of the archangel," suggesting that Michael is most probably another name for Jesus.
3. He protects God's people: Michael is described as the Prince of Israel (Dan. 10:21), the One who protects Israel (Dan. 12:1). This protection is described in military terms and portrays the Prince as a warrior. In practically all the passages in which He is mentioned there is a conflict between God's people and their enemies, and Michael is present to defend them or fight for them. The protection can also take the form of judgment in which Michael stands up and defends and delivers God's people (ibid.). Those are functions of Christ in the New Testament and confirm the suggestion that Michael and Christ are the same person, involved in leadership in the heavenly and earthly realms.
4. He is Prince of the heavenly hosts: In Daniel 8:10 there is a reference to a celestial being who performs the daily services in the heavenly sanctuary. There is only one other passage in the Old Testament in which this being is mentioned. Joshua had an encounter with a being who identified himself as the "captain [commander] of the host [army] of the Lord" (Joshua 5:14). He ordered Joshua to remove his shoes because the ground he was standing on was holy, similar to God's apparition to Moses. The context makes clear that this being was the Lord Himself (Joshua 6:2). This Prince is the same person called in other passages Prince Michael, and therefore we can identify Him with the preincarnate Christ.
So even though the Bible does not clearly identify Michael with Christ, there is enough biblical information to warrant the view that They are the same person. The name Michael stresses the fact that Christ is the supreme leader of the heavenly angels and the defender of His people as warrior, judge, and priest.