'Know' in the Bible

But we know that the law is good, if a man use it lawfully,

but if I tarry long, that thou mayest know how men ought to behave themselves in the house of God, which is the church of the living God, the pillar and ground of the truth.

forbidding to marry, and commanding to abstain from meats, which God created to be received with thanksgiving by them that believe and know the truth.