Jerusalem hath grievously sinned.... The Lord is righteous; for I have rebelled against his commandment: hear, I pray you, all people, and behold my sorrow: my virgins and my young men are gone into captivity. (Lamentations 1:8,18)
Jeremiah mourned the destruction of Jerusalem alone. He stood among the ashes weeping. Why had the city been destroyed? The city had sinned. The second explanation is "The Lord is righteous." God did it, and God was right in what He did.
This is difficult to understand, and I must say I feel totally inadequate to deal with this. I merely stand at the fringe of the sorrow of this man and find I cannot enter in. I can merely look over the wall into his garden; I am not able to walk up and down in it. He has revealed two things to us, the bitter and the sweet: Jerusalem has sinned, yet God loves Jerusalem. "Jerusalem hath grievously sinned," and "the Lord is righteous." God loved them, He said, "with an everlasting love." He brought this upon them because He is righteous.
You and I are living in a universe where there is a God, a living God, a God whose heart goes out in love and yearning over you. But I want to say this to you: if you turn your back on Him, He will judge you even though He still loves you. He is the righteous God of this universe. I am not sure I understand all that, but I know it is what He says in His Word. Someday He will make it clear to us that hell is actually there because He is a God of love and a God of righteousness and a God of holiness. The whole universe, including Satan himself, will admit that God is righteous and just in all He does. My friend, God is so great and wonderful and good we dare not trifle with Him.
Jesus could say to the scribes and Pharisees, the religious leaders of His day, "Woe unto you, scribes and Pharisees, hypocrites!" Why did He call them hypocrites? Because "...ye devour widows' houses..." (Matthew 23:14) — that was one of the reasons. My friend, if your Christianity does not affect your heart, your life in your home and in your business, and your social life, then you are a hypocrite. I didn't say it; He said it, my beloved. And He is the One who wept over these men. My eyes are dry, but His eyes are filled with tears for you and for me today. Oh, my friend, don't turn your back on the God who loves you like this! It will be tragic indeed if you do.
God does what He does because He is a righteous God. He cannot shut His eyes to evil. When His own children disobey Him, God must discipline them, even though it breaks His heart. Jeremiah reveals to us the heart of God: when Jeremiah weeps, God is weeping; when he sorrows, God is sorrowing. When we don't understand what is happening, the important thing is to trust in knowing that God is righteous in what He does. Although it broke His heart, He was right in letting Jerusalem be destroyed and in letting the people go into captivity.
—From Edited Messages on Lamentations by Dr. J. Vernon McGee