When the book of Ezekiel opens, the writer has been an exile in the land of Babylon for five years, It is about 592 B.C. This is the year Ezekiel would, at age 30, have begun his duties as a priest. Instead, all he had hoped to do, all he had trained to do, is lost. He will never serve in the temple.
It must have been a bit like going to college to become a medical doctor, doing your internship, perhaps some training in a speciality, and then being exiled to another country where your license to practice medicine is invalid.
Instead, God calls Ezekiel to be a prophet. The book opens with a heart-stopping vision of the Lord. God calls to Ezekiel and tells him to speak to his fellow exiles and this is an important point: Whereas Jeremiah spoke to those left behind in Judea, Ezekiel speaks to those who were led away. When Ezekiel prophesies against the “mountains of Israel,” he is not speaking to those who dwell in Israel. He speaks to those who live in Babylon about those left in Israel. They (those in Israel) are a “rebellious” nation, obstinate and stubborn, adulterous and wicked.
The exiles might imagine themselves in the worse shape because they are exiles. But through Ezekiel, God assures them that those in Israel are rally worse, and they are to receive the full measure of God’s wrath. If there was ever any doubt that God was in charge, the Lord would allay that doubt. Everyone would know that He is the one and only “Lord.” This assurance appears for the first time in Ezekiel in chapter 6, but it becomes a repeated refrain throughout the rest of the book.