Self-deception about Sin is a Narcotic

In his brief theology of sin, Not The Way It's Supposed To Be, Cornelius Plantinga, Jr. states that his goal is to renew our knowledge of the persistent reality of sin "that used to evoke in us fear, hatred, and grief."
Fear.
Hatred.
Grief.
Do these words describe your reaction to sin?
They should.

Plantinga goes on to lament and warn us:

Many of us have lost this knowledge, and we ought to regret the loss. For slippage in our consciousness of sin, like most fashionable follies, may be pleasant, but it is also devastating. Self-deception about our sin is a narcotic, a tranquilizing and disorienting suppression of our spiritual central nervous system. What's devastating about it is that when we lack an ear for wrong notes in our lives, we cannot play right ones or even recognize them in the performances of others. Eventually we make ourselves religiously so unmusical that we miss both the exposition and recapitulation of the main themes God plays in human life. The music of creation and the still greater music of grace whistle right through our skulls, causing no catch of breath and leaving no residue. Moral beauty begins to bore us. The idea that the human race needs a Saviour sounds quaint.
(Page xiii, emphasis added)

I often remind myself of the two theological pillars that hold up my worldview:
1) The holiness of God, and
2) The sinfulness of man.

In our Bibles we see both. And they feed off of one another.
The more holy I see my God, the more sinful I see myself.
The more sinful I see myself, the more gracious I see my God.
As the chasm grows wider between my sinful self and my holy God, the need for grace grows greater.
And grace is greater, because Christ is greater. Grace is great, because it comes through Christ.

Now the law came in to increase the trespass, but where sin increased, grace abounded all the more, so that, as sin reigned in death, grace also might reign through righteousness leading to eternal life through Jesus Christ our Lord.
(Romans 5:20-21 ESV, emphasis added)

So, do we need to heed Plantinga's warning and overcome the self-deception about sin? Must we really train our ears to hear the wrong notes (sin) in our lives? Absolutely. Perhaps the puritan Thomas Watson could sum it up best, "'Til sin be bitter, Christ will not be sweet."