'Knew' in the Bible

So remember the heights from which you have fallen, and repent [change your inner self—your old way of thinking, your sinful behavior—seek God’s will] and do the works you did at first [when you first knew Me]; otherwise, I will visit you and remove your lampstand (the church, its impact) from its place—unless you repent.

He who is having an ear -- let him hear what the Spirit saith to the assemblies: To him who is overcoming, I will give to him to eat from the hidden manna, and will give to him a white stone, and upon the stone a new name written, that no one knew except him who is receiving it.

His eyes were as a flame of fire, and on his head were many crowns; and he had a name written, that no man knew, but he himself.