Ezekiel 9:4

(4) and the LORD said to him, “Go through the midst of the city, through the midst of Jerusalem, and put a mark on the foreheads of the men who sigh and cry over all the abominations that are done within it.” 
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Obviously, to sigh and cry over the abominations of Israel, we have to know what sin is and what Godconsiders abominable. The apostle John tells us that “sin is the transgression of the law” (I John 3:4). In Romans 3:20, Paul instructs us that “by the law is the knowledge of sin.” In Romans 7:7, he reflects that he “would not have known sin except through the law.” So we must know God’s law in order to identify sin properly.

This is knowledge, pure and simple, not just emotion. Without this knowledge of the law, we would become subverted by the deceitful rudiments of this world, which are, in reality, demons. Paul writes of this in Colossians 2:8: about demonic philosophies that float around all over this world today, teaching, for instance, that abortion, bestiality, and gluttony are okay because they are simply personal expressions. Liberals here in the United States proclaim that they are acceptable choices! Nevertheless, by knowing God’s law, we understand that they are not mere personal expressions and they are not acceptable—they are indeed sins and abominations.

The psalmist writes in Psalm 119:136, “Rivers of water run down from my eyes, because men do not keep your law.” The psalmist weeps because he recognizes that people are not obeying God’s law, and he can see where it leads: to ruin and death. It is not just emotion, but it is real feeling connected with an understanding of God’s law.

— Charles Whitaker