John 3:19-20
And the ground for the sentence is this, that the light has come into the world, and yet, because their actions were evil, men have loved darkness more than the light.
John 8:55
And yet you have not learned to know Him; but I know Him, and if I say I do not know Him, I will be a liar like you. On the other hand, I do know Him and I do follow His teaching.
John 16:3
They will do this, because they have never come to know God nor me.
2 Thessalonians 2:11-12
This is why God sends them a misleading influence till they actually believe what is false,
1 John 2:3-4
By this we can be sure that we know Him -- if we practice obedience to His commands.