YOU SAID:
He who is not with me is against me.
INTO JAPANESE
私と一緒にいない彼は私に反対です。
BACK INTO ENGLISH
Not with me he is against me.
INTO JAPANESE
私と一緒ではない彼は私に反対です。
BACK INTO ENGLISH
Not with me he is against me.
That didn't even make that much sense in English.