“Return” is not necessarily a quick and simple thing. When the people of God were allowed to return to Jerusalem (and the surrounding countryside), many—if not most—of the people who had been forced into exile in Babylon had died. Thus many of the people who “returned” to their homeland were going there for the first time.
No doubt they had heard stories from their parents and grandparents, and their minds, hearts, and souls were filled with hope. But still, they had to wait. When the word came allowing them to return, it came with the reminder to “return to the Lord,” and not only their homeland.
Zechariah’s vision and words from the Lord were hopeful; after seventy years of wondering what the future would hold, if there would even BE a future, the people of God heard words of hope and promise, that God would bless the land, and them.
Yet once reestablished in their homeland, and after the Temple had (finally) been rebuilt, the people began to take God, and the blessings the Lord had promised, for granted. Not only the ordinary, day-to-day folks, but the priesthood, as well, became complacent about participating in worship, and lackadaisical about their tithes and offerings, focusing on themselves and not God. The people slowly but surely drifted away from a vibrant and vital relationship with God.
Malachi’s prophecies—far more about what the people needed to hear about their lives and what was on the future horizon—called the people back to the Lord. Without putting trust in God, without making God and worship a priority, the people were preventing themselves from finding true joy in the Lord. When God’s people return to Him, and give God their best, then God responds with incredible blessings.
Psalm 96 can be read as a response to the recognition that God is the source of every good and perfect gift; it is an opportunity, an invitation, to sing the glories of the Lord as experienced in every dimension of life.