forewarn

But I will forewarn you whom ye shall fear: Fear him, which after he hath killed hath power to cast into hell; yea, I say unto you, Fear him.

These things, my beloved, I write unto you; not that I know of any among you that lie under this error; but as one of the least among you, I am desirous to forewarn you, that ye fall not into the snares of false doctrine.