1 Corinthians 2:11
For what man knoweth the things of a man, but the spirit of a man which is in him? So the things of God also knoweth no one, but the Spirit of God.
Romans 2:15
Who shew the work of the law written upon their hearts, their conscience also bearing witness, and their thoughts among themselves accusing or even defending them,
2 Corinthians 4:2-6
not walking in craftiness, nor deceitfully corrupting the word of God, but by 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 powerful, and sharper than any two edged sword, piercing even to the dividing asunder both of the soul and spirit, both of the joints and marrow, and is a discerner of the thoughts and intents of the heart.
1 John 3:19-21
And hereby we know that we are of the truth, and shall assure our hearts before him.