'Principles' in the Bible

So we also, when we were children, were held in bondage under the elemental principles of the world.

But now that you have come to know God, or rather to be known by God, why do you turn back again to the weak and miserable elemental principles, to which you desire to be in bondage all over again?

For although by this time you should be teachers, you again need to have someone teach you the rudiments of the first principles of the oracles of God. You have come to need milk, and not solid food.

Therefore leaving the teaching of the first principles of Christ, let us press on to perfection -- not laying again a foundation of repentance from dead works, of faith toward God,