Men certainly speak peace to themselves when they do not view their sin, from the guilt of which they seek relief, with the greatest hatred imaginable. There should be an abhorrence of themselves for that sin.

If men are wounded by sin, disturbed and perplexed, and realize that there is no remedy for them except in the mercy of God and through the blood of Christ; and if such look to Him and His covenant promises, and upon this basis quiet their hearts, believing that it will indeed be well with them, and that God will be gracious to them—and yet they do not detest with utter hatred the sin in question—this is to heal themselves and not be healed by God.

This is like the great and strong wind that the Lord was near to, but the Lord was not in the wind (1 Kings 19:11)!

When a man truly looks upon Christ whom he has pierced, without whom there is no healing or peace, and mourns (Zech 12:10), his mourning will be because it was his sin that pierced Him!

…Let a man seek as he will for healing and peace, let him go to the true Physician, let him seek in the right way and let him quiet his heart in the promises of the covenant. Yet when peace is spoken, if it is not attended with hatred and abhorrence of the sin which caused the wound and was the reason for all the trouble, then this is not God’s peace but a peace of our own making.

—John Owen, The Mortification of Sin (Carlisle, PA: Banner of Truth, 1656/2004), 103-105.

Read the rest of this great work on Christian sanctification, holiness and mortification of sin (unabridged), here.