In my estimation, the key passage in the Book of Revelation is 6.9–11. John saw under the altar in heaven the souls of those who had been slain for the word of God, and they wanted to know how long before the Lord avenged their blood on those who dwell on the Earth.

Then a white robe was given to each of them; and it was said to them that they should rest a little while longer, until both the number of their fellow servants and their brethren, who would be killed as they were, was completed (Revelation 6.11).

God would fulfill their request, but He did not tell them how long it would be, because He operates on His own schedule, and it is to His glory to conceal matters (Proverbs 25.2).

Nevertheless, He comforted them, giving them white robes, telling them to rest until the rest of their brethren joined them.

Rest assured the Lord deals with our enemies, but He waits until certain things are in place before He takes His final action against them.