The most remarkable thing about self-deception is that those who are practicing it don’t know it. The Bible says that the human heart “is deceitful above all things, and desperately sick; who can understand it?” (Jeremiah 17:9) According to God, every inclination and intention of the human heart is evil. (Genesis 6:5) Our hearts are grievously incurable. When describing the condition of the heart John Calvin said, “The human heart has so many crannies where vanity hides, so many holes where falsehood lurks, is so decked out with deceiving hypocrisy, that it often dupes itself.” (Online Source)
My, what a sad state of affairs! Whatever could we do to overcome such a hopeless condition? Only one thing.
Ephesians 5:26 tells us that Christ sanctified His Bride and cleansed her by the washing of water by the Word. He does not cast her out because of her filth. He sanctities her in the Truth. The Word of God is Truth. (John 17:17) He sends forth His Word and she is healed of all her diseases. (Psalms 107:20) He applies the medicine of the Gospel of Christ crucified. Let us submit to this truth. It is the only way. Our Lord suffered that we would be made holy through his blood. (Hebrews 13:12)
“No one enjoys being cross-examined, or accused of having something wrong in their lives. But as we grow as Christians we come to the painful recognition that we have an almost unlimited capacity for self-deception. We slowly learn that we need to be stopped in our tracks by God. He uses Scripture to do this…We cannot reach our destination if we are traveling in the wrong direction.”
Sinclair Ferguson, Healthy Christian Growth, page 5.