A woman in the Bible is used as a symbol for God’s people (2 Cor. 11:2): a chaste woman stands for faithful believers, while a harlot stands for apostate/impure Christians. The woman in Revelation 12 first symbolizes Israel, to whom the Messiah came (Rev. 12:1-5); in verses 13-17 she stands for the true church that gives birth to the remnant.
This woman is portrayed as clothed with the sun and with the moon under her feet. The sun represents the glory of Christ’s character, His righteousness (Mal. 4:2). He is “the light of the world” (John 8:12), and His people are to reflect the light of God’s loving character to the world (Matt. 5:14-16). The moon, as “the lesser light” (Gen. 1:16), points to the Old Testament promises foreshadowing the work of Christ in the gospel era.
The next thing John sees in the vision was a “fiery red dragon having seven heads and ten horns” (Rev. 12:3, NKJV). This dragon is later identified as Satan (Rev. 12:9). His “tail”, symbolizing the means used to deceive (Isa. 9:14-15; Rev. 9:10), dragged a third of the stars from heaven down to the earth (Rev. 12:4). This action shows that, having fallen from his exalted position in heaven (Isa. 14:12-15), Satan was able to deceive a third of the angels. These fallen angels are the demons who assist the devil in opposing God and His work of salvation (1 Tim. 4:1).
Revelation also uses the dragon, described as “having seven heads and ten horns”, as a symbol of those agents in the world used by Satan – pagan Rome (Rev. 12:4) and spiritualism (Rev. 16:13). “The dragon is said to be Satan (Revelation 12:9); he it was that moved upon Herod to put the Saviour to death. But the chief agent of Satan in making war upon Christ and His people during the first centuries of the Christian Era was the Roman Empire, in which paganism was the prevailing religion. Thus while the dragon, primarily, represents Satan, it is, in a secondary sense, a symbol of pagan Rome”. – Ellen G. White, The Great Controversy, p. 438.
From the beginning, Satan was waiting for the Messiah-the Child to be born – in order to destroy Him. When the Messiah was finally born, Satan used pagan Rome (also symbolized as the dragon in Revelation 12:4) to try to destroy Him (Matt. 2:13-16). But the Child was “caught up to God and His throne” (Rev. 12:5, NKJV). 🙌🏾
I still have questions; studying this further here: https://www.amazingfacts.org/media-library/book/e/53/t/the-beast–the-dragon-and-the-woman
Source reference: SDA 1Q19 Quarterly