Question:
What is iniquity?

Answer:
This is a tough one to put in words on paper. It is a good question because it has made me search in Vine’s Expository Dictionary of New Testament Words. So the answer which follows are not my words, but from the dictionary.

There are different Greek words that are translated “iniquity” in the New Testament. The Greek word “anomia” means lawlessness, and wickedness (Titus 2:14), and is translated unrighteousness in 2 Corinthians 6:14. In the plural, this word means acts or manifestations of lawlessness (Romans 4:7, Hebrews 10:17).
Another Greek word that is translated “iniquity” in our Bibles is “adikia” which denotes unrighteousness, a condition of not being right, whether with God, according to His holiness and righteousness, or with man according to the standard of what man knows to be right by his conscience (2 Timothy 2:19, James 3:6). (This word for iniquity means anything unscriptural. So 2 Timothy 2:19 instructs all believers to “depart from [anything that is not according to the Word].” —Ed.)
Another Greek word is “adikema” which denotes a wrong, injury, misdeed (Acts 24:20).

 

There are two more Greek words that are translated iniquity in the New Testament and they mean bad, worthless (Ephesians 6:12), and law-breaking (2 Peter 2:16).