This statement is probably the quintessential response made by Christians when they are trying to avoid HIS commandments or to explain their aberrant behavior.
(Statement:) "HE knows what's in my heart."
(Response:) Yes, but is that a good thing?
13 "In transgressing and lying against the LORD, and departing away from our God, speaking oppression and revolt, conceiving and uttering from the heart words of falsehood." (KJV)
9 "The heart is deceitful above all things, and desperately wicked: who can know it?" (KJV)
11 "The LORD knoweth the thoughts of man, that they are vanity." (KJV)
26 "He that trusteth in his own heart is a fool: but whoso walketh wisely, he shall be delivered." (KJV)
20 "For there is not a just man upon earth, that doeth good, and sinneth not." (KJV)
20 "And again, The Lord knoweth the thoughts of the wise, that they are vain." (KJV)