We may ask “Why didn’t God send Michael with the message for Daniel in the first place so that there would not have been a three-week delay?” The fact is that the Bible doesn’t tell us why God sent an angel whom He undoubtedly knew would not be able to break past the “prince of Persia” without the help of Michael. In fact, we have no idea why God would use any angel to deliver a message to someone! Why didn’t He go personally, or speak to Daniel audibly, or bring Daniel temporarily to heaven to tell him? We just don’t know.
But does this passage prove that there are constant battles in the spiritual realm between God’s angels and Satan’s angels? No, it only proves that, several thousand years ago, there was one three-week struggle between one of God’s weaker angels and one of Satan’s angels named “the prince of Persia,” a battle, which, if God had so willed, would never have occurred. The only other angelic battle mentioned in the entire Bible is the one future war in heaven, recorded in the book of Revelation. That’s it. There may have been other angelic battles that have occurred, but it would be an assumption on our part to so conclude.