Just as they were a curse among the nations, so Jehovah will save them, and they will be a blessing. They should not fear, but their hands should be strong. Just as He intended to do harm to them when their fathers provoked Him to anger, and He did not repent, so again He intends in these days to do good to Jerusalem and to the house of Judah (vv. 13-15). God will be good to them in every way.
Finally, the fasts of the fourth month and the fifth month, and the fasts of the seventh month and the tenth month, will become joy and rejoicing and cheerful feasts to the house of Judah (v. 19). Instead of fasts there will be feasts full of good food for the enjoyment of the people of Israel.
The nations will come to Israel to entreat the favor, the grace, of Jehovah, and the children of Israel will be priests to them (vv. 20-23). By this time the entire nation of Israel will be a priesthood. They will teach the Gentiles, the nations, to know God's way and God's person, and they will teach them to worship and serve God. As priests, they will bring the nations into the presence of God that they may be enlightened, corrected, and favored with all the riches of God. This is the priesthood. In the one thousand years of the kingdom, after the Jews are saved at the Lord's coming back, they will become the priests to teach all the repentant nations.
Not just one kind of people but peoples, even the inhabitants of many cities from different countries, will come to Israel and say, "Let us go at once to entreat the favor [grace] of Jehovah and to seek Jehovah of hosts; and the other: I will go, too" (v. 21). Verse 22 goes on to say, "Indeed, many peoples and strong nations will come to seek Jehovah of hosts in Jerusalem and to entreat the favor of Jehovah." I hope that one day in all the local churches the situation will be like this. Whenever someone would say, "Let us go to the meeting," another would say, "I will go, too." This will be the situation in the millennium. Not only all the people of Israel but also the Gentiles who are living with them will seek God.