1. Apostasy of church
2. Sin on earth climaxed
3. Restrainer or guard of Antichrist influence on earth removed/relieved of his job of holding him (antichrist) back from fully attacking and destroying all of humanity. This is most likely a mighty Angel.
This 4th one is more before Christ’s return but as Christians we should be participating in and praying for this.
4. Gospel gets to ends of earth