'Enemy' in the Bible

Ye have heard that it was said, Thou shalt love thy neighbor, and hate thine enemy:

but while men slept, his enemy came and sowed tares also among the wheat, and went away.

And he said unto them, An enemy hath done this. And the servants say unto him, Wilt thou then that we go and gather them up?

and the enemy that sowed them is the devil: and the harvest is the end of the world; and the reapers are angels.