Who are the host of heaven?
The "host of heaven" has two basic meanings and the meaning is determined by the context of the passages used in Scripture. Both heavenly (celestial) bodies -- the sun, moon, stars and angels are referred to as the "host of heaven." These two meanings also often overlap when angels are sometimes also referred to as stars (Judges 5:20; Job 25:5; 38:7, Revelation 1:20.
In the book of Deuteronomy the Lord warned not to worship the celestial stars and created heavenly bodies instead of worshipping Him:
"And take heed, lest you lift your eyes to heaven, and when you see the sun, the moon, and the stars, all the host of heaven, you feel driven to worship them and serve them, which the LORD your God has given to all the peoples under the whole heaven as a heritage" (Deuteronomy 4:19).
The host of heaven can also be reference to evil angels. In the Old Testament passage below, evil angels are referred to as "the host of heaven." In the struggle between the evil King Ahab and the prophet Micah the host of heaven standing before God are evil angels (spirits).
"Then Micaiah said, "Therefore hear the word of the LORD: I saw the LORD sitting on His throne, and all the host of heaven standing by, on His right hand and on His left. And the LORD said, 'Who will persuade Ahab to go up, that he may fall at Ramoth Gilead?' So one spoke in this manner, and another spoke in that manner. Then a spirit came forward and stood before the LORD, and said, 'I will persuade him.' The LORD said to him, 'In what way?' So he said, 'I will go out and be a lying spirit in the mouth of all his prophets.' And the LORD said, 'You shall persuade him, and also prevail. Go out and do so'" (1 Kings 22:15-28).
Luke uses the words "heavenly host" when describing heavenly beings, heavenly angels:
"And suddenly there was with the angel a multitude of the heavenly host praising God and saying: "Glory to God in the highest, and on earth peace, goodwill toward men!"
According to the Holman Illustrated Bible Dictionary, the phrase "host of heaven" came into use because of the close connection between the realms of the earth and heaven in ancient thought. The word "host" is basically a military term connected with fighting and waging war.
When Jesus Christ returns at the end of the Tribulation he will bring with Him, a heavenly host or "armies" from heaven (Revelation 19:14) as he fights the final battle to regain planet Earth and set-up His millennial kingdom.