Joel 2:1  “…For the day of the LORD is coming…”
Day of judgment.  Day when the LORD will finish all things and complete His plans.  Used generically as days of judgment, but the one at the end of time is main one referenced.

2  “…A people come, great and strong…
The locusts in this context, but also referencing the armies of the Tribulation at the end.  Prophecy is a parallel to the last days.

3  “A fire devours before them, And behind them a flame burns; The land is like the Garden of Eden before them, And behind them a desolate wilderness…”
Moving across the land, destroying everything before them and leaving nothing but destruction and desolation behind them.

4-6  “Their appearance is like the appearance of horses; And like swift steeds, so they run.  With a noise like chariots Over mountaintops they leap, Like the noise of a flaming fire that devours the stubble, Like a strong people set in battle array.  Before them the people writhe in pain; All faces are drained of color.”
Mirror passage in Revelation 9.  Sun and moon were darkened by the smoke from the pit.  The locusts arose from it.  “The shape of the locusts was like horses prepared for battle. On their heads were crowns of something like gold, and their faces were like the faces of men.  They had hair like women’s hair, and their teeth were like lions’ teeth.  And they had breastplates like breastplates of iron, and the sound of their wings was like the sound of chariots with many horses running into battle.”  “In those days men will seek death and will not find it; they will desire to die, and death will flee from them.”  This is during the Tribulation, the last seven years of normal time on earth before the Millennial reign of Christ.  The final judgment of God upon man and what He uses to bring the nation of Israel back to Himself.

8  “…Though they lunge between the weapons, They are not cut down”
Sounds like attempts are made to stop them, but they are able to get through any attack.

9  “…They climb into the houses, They enter at the windows like a thief”
I’ve always assumed they were rather large, I guess due to the mention of them looking like horses.  But it appears they may be small, like scorpions.  That would explain how they are able to evade any attempts to knock them down as they fly about and how they are able to enter through windows into houses.

10  “…The sun and moon grow dark, And the stars diminish their brightness”
This happens within the context, then and at the last.  Some today try to take things that happen and fit them into the text, but that is backwards.  You can’t fit events into the text without viewing them from the text.  The sun and moon growing dark happened then and will happen again during the Tribulation.

11  “…For the day of the LORD is great and very terrible; Who can endure it?”

12  “…Turn to Me with all your heart, With fasting, with weeping, and with mourning”
Here as at the last, the people are given a chance to repent and return to God.  At the last, the time is short, and those living then eventually run out of opportunities to repent.

13  “…rend your heart, and not your garments…”
Genuine heart change, not just an outward appearance.

14  “Who knows if He will turn and relent, And leave a blessing behind Him— A grain offering and a drink offering For the LORD your God?”
It is God who provides us with the resources to praise and worship Him.  We have nothing on our own.

25  “So I will restore to you the years that the swarming locust has eaten, The crawling locust, The consuming locust, And the chewing locust, My great army which I sent among you.”

28  “…That I will pour out My Spirit on all flesh…”
The coming of the Holy Spirit to indwell mankind, all those who receive Christ.  No distinction between ethnic background, social status, or gender.  All who accept Him are partakers.

30-31  “And I will show wonders in the heavens and in the earth: Blood and fire and pillars of smoke.  The sun shall be turned into darkness, And the moon into blood, Before the coming of the great and awesome day of the LORD.”
Within the context, same as before, during the time of the last days.  The family of God is not a factor.  During the Tribulation.

32  “…whoever calls on the name of the LORD Shall be saved”
After Christ, all that is needed for salvation is to trust in Him and call upon His name.  No more sacrifices and trying to keep all the Law.  Christ has fulfilled all requirements.  All that is needed is trust in Him.  This is offered even through the Tribulation up to a point.

I hope you enjoy reading and studying His word.  May it accomplish what He desires.  Please feel free to comment or post questions.  Thanks for reading!

Scripture taken from the New King James Version®. Copyright © 1982 by Thomas Nelson. Used by permission. All rights reserved.