'Know the Truth' in the Bible

“Then I wished to know the exact meaning of the fourth beast, which was different from all the others, extremely dreadful, with teeth of iron and claws of bronze, which devoured, crushed and trampled down what was left with its feet,

And you will know the truth [regarding salvation], and the truth will set you free [from the penalty of sin].”

The faith which you have [that gives you freedom of choice], have as your own conviction before God [just keep it between yourself and God, seeking His will]. Happy is he who has no reason to condemn himself for what he approves.

He must correct those who are in opposition with courtesy and gentleness in the hope that God may grant that they will repent and be led to the knowledge of the truth [accurately understanding and welcoming it],

I have not written to you because you do not know the truth, but because you do know it, and because no lie [nothing false, no deception] is of the truth.