A woman must stay with her husband as long as he lives. But if her husband dies, she is free to marry any man she wants, but she must marry another believer.
The people of Judah have broken their promises. They have done something God hates in Israel and Jerusalem: The people of Judah did not respect the Temple that the Lord loves, and the men of Judah married women who worship foreign gods.
But if those who are not believers decide to leave, let them leave. When this happens, the Christian man or woman is free. But God called us to live in peace.