'Know' in the Bible

Adulteresses! Don’t you know that friendship with the world is hostility toward God? So whoever wants to be the world’s friend becomes God’s enemy.

You don’t even know what tomorrow will bring—what your life will be! For you are like smoke that appears for a little while, then vanishes.

let him know that whoever turns a sinner from the error of his way will save his life from death and cover a multitude of sins.