'Principles' in the Bible

For when by reason of the time ye ought to be teachers, ye have need again that some one teach you the rudiments of the first principles of the oracles of God; and are become such as have need of milk, and not of solid food.

Wherefore leaving the doctrine of the first principles of Christ, let us press on unto perfection; not laying again a foundation of repentance from dead works, and of faith toward God,