Joel 2:12 - Here Joel gives the solution to judgment at anytime throughout history: believe in Christ. This was the solution to the locust infestations; this will be the solution to the coming Assyrian invasions; and this will be the solution during the future Tribulation. It is the same "yesterday, today and forever" -- Christ.

The three terms "fasting, weeping, and mourning" mean focus on God, and all three will be demonstrations of faith.   “Fasting” is denial of desires to focus on God and get serious.  “Weeping” sign of true sorrow and also a cleansing action.  “Mourning” usually refers to the time when we loose someone in death to put that behind us and move on.  When we truly turn our hearts to God we “fast” and devote ourselves to seeking His will, we “weep” in sorrow before Him, we “mourn” the death of our old self and move on with Him.

In this verse, Joel speaks of evangelism during the Tribulation. Our Lord described this evangelism in Matthew 24:14.  So we see that not one individual of the Tribulation has an excuse for not believing.

There are four phases of evangelism during the Tribulation.

1.        According to Revelation chapter 7, there are 144,000 evangelizing Jews. Twelve tribes of 12,000 each.

2.        The second phase is composed of the converts of the 144,000. They, too, begin an intense period of evangelization. For their efforts many of them are martyred. This phase is cited in Revelation 14:12,13.

3.        The third phase of evangelism is performed by the two witnesses, Moses and Elijah, present the gospel to the entire world, not only while alive but through their dead bodies being raised. This phase is related in Revelation 11:1-14.

4.        The fourth phase of evangelism is accomplished by flying angels proclaiming the salvation of God, Revelation 14:6,7.

Joel 2:13 - In this verse, Joel demands precisely what the prophet Jonah later demanded of the Ninevites, a change of mind toward the Savior of the Universe -- belief in Christ.

"Rend your heart" -  the Jews of the Tribulation must alter the manner in which they think of Christ. And "not your garments" is a reference to the wailing of lamentation. The lamentation here is the fear of circumstances, i.e., the advancing armies, the lack of food, death, etc., and the belief that there exists no solution to these crises. Joel says do not just tear your garments and cry in fear, worry and terror. Instead, rend your heart -- believe in Christ.  Here is the answer to the tragic conditions of the Tribulation.

"Return" to the Lord your God; to the God of your fathers.  "He is gracious" is a direct reference to God the Father judging the Son on the Cross.  This is a gift to mankind and is thus "gracious" in the extreme. "And compassionate," refers to the execution of the Father's Plan for the salvation of all -- this is mercy or grace in action.

"Slow to anger" means that God loves His own perfect Righteousness which the believer has because of grace.  Thus God may be patient. "Abounding in love" speaks of the reason for God's graciousness, propitiation -- He was satisfied with the work of Christ on the Cross.

"And he relents from sending calamity" means that He does not judge us as we deserve (calamity), but instead "relents," which means He found a way to avoid judging us -- by judging His own Son for our sins.

Joel 2:14 -  "Who knows?" The believer knows and is confident that our Lord will be gracious and that He will return as promised in Scripture.  And “have pity and leave a blessing.”  The phrase "have pity" pertains to the restoration of Israel at the Second Advent. And the clause "leave a blessing" concerns the gift of perfect environment, and includes the heavenly Jerusalem of the Millennium.

"The grain offerings and drink offerings" relates the function of the Levitical sacrifices during the Millennium: they will become the communion table of the Jews, looking back on the Cross, just as we do during the Church Age.  This use of the sacrifices in the Millennium is also related and supported in Ezekiel, chapters 40-47.

Joel 2:15 - 16 present the Millennial Reign of Christ and the Regathering of Israel.  Again we have the blowing of the trumpet as a signal, just as in 2:1.  Here, however, the trumpet signals the gathering of the people rather than a warning blast.  A "holy fast" is to be declared; this refers to the designation of a special worship period, a time to concentrate on our Lord. In effect, this is a 'celebration,' in every good sense of the word, and the celebration is to last 1000 years, for the King of Kings and Lord of Lords now resides and rules on earth.   Finally, the term "assembly" refers to the saved Jews gathering to worship.

The phrase, "gather the people," designates the end of the Diaspora, which is the dispersion or scattering of the Jews throughout the world during the Church Age. After the Second Advent the Jews will be restored to Israel and the four unconditional covenants will be fulfilled. This also implies the judgement where the tares (the unbelievers) go to the Lake of Fire, and the wheat (the believers) enter the Millennium.

The regathering of Israel is described in Isaiah 5:26-30, and Zechariah 10:6-12. The "elders" means that those ruling the country stop their governmental functions to attend the assembly. Too, the "children" means that school is out. And those "nursing" means that young mothers and their babies attend. And note that these babies, although not believers because they have not yet passed the age of accountability, are present. The implication, then, is that babies that die before the age of accountability are automatically saved and enter heaven.  All these people bypass the Judgement of Fire.

Joel 2:17 - Here Joel introduces a totally different idea, the idea of praying for the deliverance of one's country. The "weeping" of the priest refers to offering prayer in a period of public or national crisis. The "porch" is the east porch of Solomon's Temple, and means that as the priests go about their functions in the Temple, they are to pray for the nation. How are they to pray? They are to petition God to "spare" the nation, or to have compassion on Israel. This is a demand for mercy (grace in action) based upon who and what God is, not upon any merit found in the Jews. "Inheritance" is a reference to the 4 unconditional covenants between God and Israel: the Abrahamic, Davidic, Palestinian, and New Covenants to Israel. "Scorn" means discipline from God, such as the scattering of Israel or its military occupation/rule by other nations. And the phrase "a byword among the nations" means "a hissing" or a "disgrace" among the Gentile nations. In other words, if Gentile nations (the Assyrians or the King of the North) are allowed to conquer Israel, then the Gentiles will ask, "Where is their God?" The Gentiles will be, in effect, stating that God is impotent and unfaithful, for He has not kept His covenants with Israel.

Joel 2:18 - "To become jealous for", means that God becomes "zealous for" His people, His holy nation. This phrase is also used in Ezekiel 39:25 and Zechariah 1:14 and 8:2. Thus we see the contrast between the two aspects of the Day of the Lord: the first is found in Zephaniah 1:18, "wrath;" the second is found here and in Nahum 1:2, "the fire of His zeal." Thus Christ at the Second Advent is zealous for those who are believers, and He is terrible for those who are unbelievers. And "to take pity on his people" means that God has compassion based upon grace, love and mercy: God's love finds a way.

Joel 2:19 - Here, in verse 19, the Lord answers the prayers of verse 17. Principle: a nation may be saved or regain its greatness through prayer. This is quite a thought and demonstrates the power of prevailing prayer.

"Corn, wine and oil" refer to economic and agricultural prosperity. And "never again an object of scorn" means that Israel will receive no more discipline from God; the restoration of Israel will take place.

Joel 2:20 - Here we have another reference to the King of the North during the Tribulation. Our Lord will push this army back, it will be trapped and destroyed between the "eastern sea," which is the Dead Sea and the "western sea," which is the Mediterranean Sea. And Daniel 11:45 confirms this destruction site of the King of the North. "He (the King of the North) will pitch his royal tents between the seas (east and west) at the beautiful holy mountain. Yet he will come to his end, and no one will help him."

"The stench" refers to the great slaughter and the dead bodies of the King of the North's army at our Lord's return. This stench rises in contrast to the "sweet smell of victory" which rose as our Lord hung on the Cross. And both odors carry the smell of perfect Justice and Righteousness; however, one indicates death while the other provides salvation and indicates eternal life. This great slaughter is described in Ezekiel 39:11.

The final phrase in verse 20, "surely he has done great things," refers to Jesus Christ. And the "great things" He has accomplished, He has accomplished because of His perfect Love. Salvation comes through this Love, and deliverance and restoration of the Jews at the Second Advent also come through this Love.