Book of Joel Chapter 3 Vs. 16

 The Lord Judges the Nations

The LORD also shall roar out of Zion, and utter his voice from Jerusalem; and the heavens and the earth shall shake: but the LORD will be the hope of his people, and the strength of the children of Israel. Joel 3:16

LORD also shall... God will personally lead His armies of heaven against those of the Antichrist (Joel 2:11; Isa. 63:1-5; Zec. 14:1-5; Mat. 24:29-31; 2Thes. 1:7-10; Jude 1:14-15; Rev. 11:15; 19:11-21).

and utter his... Christ, the Lamb, shall now appear as the Lion of the tribe of Judah, and utter his voice in his providence and judgments on the behalf of his church and people, signified by Zion and Jerusalem.

And therefore, said to roar and utter his voice from thence; he will be heard far and near, and strike terror in the hearts of his enemies (see Jer. 25:30).

and the heavens... will produce cosmic disorder (cf. Joel 2:10-11; Rev. 16:16, 16:18), Great revolutions will be made in the world, both in church and state, among the antichristian powers. And such as will also make them shake and tremble, as well as alter the form and frame of things among them (see Rev. 16:18). Changes in government, civil and ecclesiastic, are sometimes signified by such phrases (Hag. 2:6).

be the hope... The object, author, ground, and foundation of their hope of salvation here and hereafter. In whom they may hope for and expect safety and security in the worst of times; since he will be their "refuge", or their "harbor". He will then demonstrate that He is Israel’s Refuge (cf. Psm. 46:1; 62:8; Isa. 25:4).

As it may be rendered; to whom they (God's people) may have recourse, to shelter and be screened from the rage and wrath of their enemies. And where they will be safe, till the indignation of God be over and past; and while calamities and judgments are upon the unchristian and ungodly world, they (God's people) will have nothing to fear amidst these storms, being in a good harbor.

and the strength... Of all such who are Israelites indeed, the Lord's chosen, redeemed, and called people, both Jews and Gentiles. The author and giver of their spiritual strength.

To exercise grace; to wrestle with God in prayer; to withstand spiritual enemies; to bear afflictions patiently, and to persevere to the end. Or he is their "fortress"; their strong hold and place of defense, where they are safe from every enemy, free from all distresses, enjoy solid peace and comfort, and have plenty of provisions (Isa. 33:16).

When Jesus comes to the earth as King of kings and Lord of lords, He will set His feet on the Mount of Olives, and it will cleave in two.

Zec. 14:4 "And his feet shall stand on 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."

Jesus will enter the eastern gate, and set up His reign in Jerusalem.

Acts 4:12 "Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved."

Jesus will reign as King. He is our Salvation.

The Lord will emerge from His sanctuary in Jerusalem in theophanic splendor (Joel 3:16; cf. Amos 1:2). His thunderous battle cry(cf. will roar… and thunder) will produce cosmic disorder (cf. Joel 2:10-11; Rev. 16:16, 16:18). He will then demonstrate that He is Israel’s Refuge (cf. Psm. 46:1; 62:8; Isa. 25:4) and Stronghold (cf. Psm. 9:9; 18:2; 27:1; 37:39; 43:2; 144:2).