Here is where God gave the prophecy of Lord Jesus' future return to this earth on the "day of the Lord", and His gathering His saints and bringing them to Jerusalem with Him. And then immediately begins His future "thousand years" reign with His elect over the unsaved nations as written in Rev.20...
Zech 14:1-9
14 Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.
2 For I will gather all nations against Jerusalem to battle; and the city shall be taken, and the houses rifled, and the women ravished; and half of the city shall go forth into captivity, and the residue of the people shall not be cut off from the city.
Where else did Jesus warn about the coming battle of armies gathered around Jerusalem for the end of this world? In Revelation 16 He specifically warned about that battle with the idea of "Armageddon". He also revealed about it in Revelation 19 on the day of His future coming on a white horse wielding a sword, and also in Ezekiel 38-39, even giving us a specific nation alignment of the nation's armies that will come up against Israel on that last day. Zephaniah 3 shows this event of God gathering those nations against Jerusalem is so He will pour out His cup of indignation on them, which is pointing to His consuming fire burning those armies up.
3 Then shall the LORD go forth, and fight against those nations, as when He fought in the day of battle.
Did you not know God fought a previous battle against Satan in the old world before this present world we are in today? Revelation 12:3-4 shows that Satan had rebelled with a similar beast system in the old world that had ten horns, seven heads, but only seven crowns. The final beast at the end of this world is to have "ten crowns" per Rev.13.
4 And His feet shall stand in that day upon the mount of Olives, which is before Jerusalem on the east, and the mount of Olives shall cleave in the midst thereof toward the east and toward the west, and there shall be a very great valley; and half of the mountain shall remove toward the north, and half of it toward the south.
Acts 1 shows us when and how Lord Jesus ascended to Heaven in a cloud. The two angels that appeared to His Apostles there which saw it said Jesus will return "in like manner" as they saw Him go into Heaven. So here it is, Jesus' future return to the Mount of Olives where He ascended to Heaven from. Can't get any more plain than that above description.
5 And ye shall flee to the valley of the mountains; for the valley of the mountains shall reach unto Azal: yea, ye shall flee, like as ye fled from before the earthquake in the days of Uzziah king of Judah: and the LORD my God shall come, and all the saints with Thee.
That shows Jesus is going to bring His faithful Church with Him there to that Mount of Olives east of Jerusalem on the day of His future return.
6 And it shall come to pass in that day, that the light shall not be clear, nor dark:
7 But it shall be one day which shall be known to the LORD, not day, nor night: but it shall come to pass, that at evening time it shall be light.
That is a similar description that Jesus said in The Gospel about no man knowing the day or hour of His future return, but only that The Father knows that time. So that is marking these events here definitely to be about His future return.
8 And it shall be in that day, that living waters shall go out from Jerusalem; half of them toward the former sea, and half of them toward the hinder sea: in summer and in winter shall it be.
God's River was once upon this literal earth, per Genesis 2. It is described having return per the Ezekiel 47 chapter. That is what these "living waters shall go out from Jerusalem" is about. That will begin with Christ's future return to this earth and for His reign over all the earth.
9 And the LORD shall be king over all the earth: in that day shall there be one LORD, and His name one.
KJV
That further confirms what timing these events are for, i.e. for when Jesus returns. Then there won't be many religions or faiths, but only One God over all peoples and over all the earth. That is point to Christ's future literal reign on earth with His elect.
All this is so simple. God's consuming fire is linked with many of those other "day of the Lord" examples I gave, and this Zech.14 example makes plain on that day will be Christ's return to take reign over all the earth. So The Bible is like I declared, that on the last day of this world the "day of the Lord" will occur which will usher in Christ's return, and burn man's works off this earth by God's consuming fire at the same time, and literally burning those armies coming out of the northern quarters, leaving a remnant of them that will bow to Christ.