Joel 3:21

For I will cleanse their blood - נקיתי nikkeythi , I will avenge the slaughter and martyrdom of my people, which I have not yet avenged.

Persecuting nations and persecuting Churches shall all come, sooner or later, under the stroke of vindictive justice.

For the Lord dwelleth in Zion - He shall be the life, soul, spirit, and defense of his Church for ever. This prophet, who has many things similar to Ezekiel, ends his prophecy nearly in the same way:

Ezekiel says of the glory of the Church, שמה יהוה Yehovah shammah , The Lord Is There.

Joel says, בציון שכן יהוה Yehovah shochen betsiyon , The Lord Dwelleth in Zion.

Both point out the continued indwelling of Christ among his people.