Who can understand his errors? 
“Who can understand his errors? Cleanse me from secret faults.  Keep back. Your servant also from presumptuous sins; Let them not have dominion over me. Then I shall be blameless, And I shall be innocent of great transgression.” Psalm 19:12-13 (NKJV)
 When David first saw Bathsheba, sent for her, recalled her husband from war and subsequently plotted to have him killed, he felt okay.
 He did not immediately realize that he was in error.
 He felt smart, wise, and very confident in himself that he could handle any challenge. 
Until Nathan confronted him. (2 Samuel 12) 
What are you doing today that you think you are brilliant and wise? 
Are all your ways openly pleasing to God? 
Your heart could be deceitful and allow you to continue in sin without realizing it. 
“How can a young man stay pure? Only by living in the word of God and walking in its truth. I have longed for you with the passion of my heart; don’t let me stray from your directions!” Psalm 119:9-10  (TPT) 
Judas initially thought he was striking a good deal with those who wanted to kill Jesus. 
Thirty pieces of silver?
 That was a significant“breakthrough.”(Matthew 26:15)
 “Just hug the Master and be instantly rich” he must have thought 
Later he realized he had betrayed an innocent man.
 Ananias and Sapphira too were smart and ahead of their game.
 No one will know!!! 
It landed both of them with early death. (Acts 5:1-11)
 What is going on in your heart right now?