“我要为你而努力”英文怎么表达

I will do my best for you !

I'll fight for you.
如果是对女生说的话，这句话更浪漫:)
我要做一名骑士，为你而战。

简单的说就是I'll work hard for your case.

I will make efforts for you.

I will exert myself for you!

I would like to work hard for you