'Enemy' in the Bible

"You have heard that it was said, 'Love your neighbor' and 'Hate your enemy.'

But while his people were sleeping, his enemy came and sowed darnel in the midst of the wheat and went away.

And he said to them, 'An enemy has done this!' So the slaves said to him, 'Then do you want us to go [and] gather them?'

And the enemy who sowed them is the devil, and the harvest is the end of the age, and the reapers are angels.