Romans 1:21
so that they are inexcusable; because having thus known God they glorified Him not as God, neither were they thankful; but were infatuated by their own reasonings, and their heart being void of understanding was darkened.
Romans 1:28-30
And as they were not careful to acknowledge God, God gave them up to an undiscerning mind to do things that were not fit to be done:
2 Corinthians 6:15
what concord hath Christ with Belial? or what part hath a believer with an infidel?
John 8:55
And yet ye know him not; but I know Him: and if I should say, That I know Him not, I shall be like you, a liar: but I know Him, and obey his word.
John 16:3
And these things will they do unto you; because they have not known the Father, nor me.
John 17:3
and this is life eternal, to know Thee the only true God, and Jesus Christ whom thou hast sent.