1 Corinthians 2:11
For who of men knows the things of a man, except the spirit of the man that is in him? even so the things of God no one has known, except the Spirit of God.
Romans 2:15
who, indeed, show the work of the law written in their hearts, their conscience testifying with it, and between one another their thoughts accusing or even excusing them;)
2 Corinthians 4:2-6
but we renounced the hidden things of shame, not walking in craftiness, not handling the word of God deceitfully; but, by the manifestation of the truth, commending ourselves to every man's conscience in the sight of God.
Hebrews 4:12-13
For the word of God is living, and effectual, and sharper than any two-edged sword, and piercing even to a dividing of soul and spirit, of both joints and marrow, and is a discerner of the thoughts and intents of the heart.
1 John 3:19-21
Hereby we shall know that we are of the truth, and we shall assure our heart before Him;