'Enemy' in the Bible

Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy.

But I say to you, love your enemy and pray for those who persecute you,

But while men slept, his enemy came and sowed tares among the wheat, and went his way.

He said unto them, An enemy hath done this. The servants said unto him, Wilt thou then that we go and gather them up?

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