You stop being an enemy to yourself.

你不再是自己的敌人。

You must be capable of being an enemy to the people you love most if they're strong enough to bear it.

如果你最爱的人足够强大能承受攻击，你必须有能力成为他们的敌人。

The prosecutor said that he would now bring forward his witnesses, who would prove that Charles Darnay was an enemy to England and that he deserved severe punishment.

检察官说他现在要传唤他的证人， 他们将证明查尔斯达尔内是英国的敌人， 他应该受到严厉的惩罚。

If you listen carefully to what he says and do all that I say, I will be an enemy to your enemies and will oppose those who oppose you.

" 你若实在听从他的话，照着我一切所说的去行，我就向你的仇敌作仇敌，向你的敌人作敌人。