'Know' in the Bible

And dost thou wish to know, O vain man, that the faith apart from the works is dead?

who do not know the thing of the morrow; for what is your life? for it is a vapour that is appearing for a little, and then is vanishing;

let him know that he who did turn back a sinner from the straying of his way shall save a soul from death, and shall cover a multitude of sins.