armies in heaven
Armies is στρατεύματα [strateumata] : troops,1 armed force.2 The army is composed of saints which denotes those who are set apart and dedicated to God. This term includes both angels (e.g., Dan. Dan. 8:13) and men (e.g., Ps. Ps. 16:3; Ps. 34:9; Acts Acts 9:13). Joel indicates that Gods mighty ones will be among themalmost certainly a reference to angels (Joel Joel 3:11).
Scripture records rare glimpses into the abilities of these mighty ones. When Hezekiah petitioned the LORD for defense against Sennacherib, the king of Assyria, the LORD sent His angel who killed 185,000 Assyrians in one night (2K. 2K. 19:35). When forces came against Elisha and his servant became alarmed, Elisha prayed that the LORD might open his eyes: And behold the mountain was full of horses and chariots of fire all around Elisha (2K. 2K. 6:14 cf. Ps. Ps. 68:17).
Paul also indicates that angels will attend the revealing of Christ to those upon whom He will take vengeance:
. . . since it is a righteous thing with God to repay with tribulation those who trouble you, and to give you who are troubled rest with us when the Lord Jesus is revealed from heaven with His mighty angels, in flaming fire taking vengeance on those who do not know God, and on those who do not obey the gospel of our Lord Jesus Christ. These shall be punished with everlasting destruction from the presence of the Lord and from the glory of His power, when He comes, in that Day, to be glorified in His saints and to be admired among all those who believe, because our testimony among you was believed. 2Th. 2Th. 1:7-10 [emphasis added]We also know, from what the angel previously told John, that those who are with Him are called, chosen, and faithful (Rev. Rev. 17:14+). This describes believers. Thus, those returning with Christ include both angels and believers, although it may be that only believers are on horses: A factor which causes hesitation in identifying the armies as angels, however, is the unlikelihood that they would be on white horses as their leader is.3 See commentary on Revelation 17:14.
The word [armies] is in the plural number, meaning that at least two separate armies will return with Him. One army is known as hosts of the Lord , or the angelic army [Mtt. Mat. 16:27]. . . . Another army that will return with Jesus is the army of the Church saints who had been raptured previously, . . . [Jude Jude 1:14-15].4Although it is possible that the plural form, armies, denotes two categories of soldiers, this is not necessarily so because the same force is later referred to as His army (στρατεύματος [strateumatos] , singular) (Rev. Rev. 19:19+).
Since The 70th Week of Daniel is not over until Christ has returned to earth, it seems that the OT saints have not yet been resurrected (Dan. Dan. 12:2). Therefore, they are not a part of the army which rides forth. If the resurrection of the Tribulation saints occurs at the institution of the Millennial Kingdom (they lived, Rev. Rev. 20:4+)and the Tribulation has not yet officially endedneither will they have been resurrected to participate in the army. This infers that the human element of the army is limited to the previously-raptured Church.
clothed in fine linen, white and clean
All the saints, both angels and believers, appear in bright, white attire (Rev. Rev. 3:4+; Rev. 15:6+). The white clothing of the angels is a reflection of their elect status and the glory of God. The white clothing of the believers indicates the righteousness of Christ which is attributed to them on account of His redeeming blood (Rev. Rev. 1:5+; Rev. 7:14+). See commentary on Revelation 19:8.
1 Frederick William Danker and Walter Bauer, A Greek-English Lexicon of the New Testament and Other Early Christian Literature (Chicago, IL: Uersity of Chicago Press, 2000), 770.