It is fair to say that iniquity is not a popular word in modern English. It sounds very old fashioned and is probably used almost exclusively in a religious context to refer to another unpopular concept: sin. In Psalm 51 both of these words can parallel each other, as they do elsewhere in the Hebrew Bible. They can be joined by a third word, transgression. This word also parallels the other two. We can see this is the two opening verses of Psalm 51 which comprise three parallel statements:
Have mercy on me, O God,
according to your steadfast love;
according to your abundant mercy
blot out my transgressions.
Wash me thoroughly from my iniquity,
and cleanse me from my sin.
Psalm 51:1–2, NRSV
Despite this apparent equivalence of all three words, they each have a different meaning in the original Hebrew. In his magisterial commentary on the Psalms, John Goldingay helpfully uses three different, and less religious words to help capture the original Hebrew [Goldingay, 2007, p.126]:
Transgressions → rebellions
Iniquity → waywardness
Sin → failure
Goldingay explains that behind rebellions lies a Hebrew word which means turning against authority. Similarly, the word translated failure refers to missing a target. This is not accidental failure, there is a sense of responsibility and choice here.
Finally, to iniquity. This old-fashioned word represents a Hebrew word meaning waywardness, or a deliberate deviation from the right path. Whether we are people of faith, or not, I think we all know there are times when we make a decision that sets us on a different path. We also know that sometimes our judgement is poor, we know that we are choosing a wrong path. The problem is that all too often one bad turn leads to another. The psalmist knows that we sometimes need a God-given bath—a factory reset to overwrite our iniquity. By asking God we can be cleansed, washed, and our wrong path blotted out of our copy book. In our next post we hear from someone who was convinced that we all needed to respond to this message.
John Goldingay, The Psalms Volume 2: Psalms 42–89, Baker Commentary on the Old Testament Wisdom and Psalms, Baker Academic, 2007.