I don't think that's wrong, but I think we could do better. As it stands it seems a little clumsy and un-idiomatic to me. We migh simplify it to
Cum Deo Non Timeo
That is literally, "With God I Do Not Fear".
But this, like your original version, runs into what one might call a "cultural" problem. To someone brought up in ecclesiastical Latin, you must understand, fear of the Lord was presented as a Very Good Thing; it is mentioned positively over and over in Scripture, and it was in fact one of the Seven Gifts of the Holy Ghost (the others being wisdom, understanding, counsel, fortitude, knowledge, and piety). Both the original and the emended phrase above thus run (it seems to me) some risk of ambiguity.
Why not borrow the words of Psalm CXVIII: 6:
Dominus mihi adjutor: non timebo.
The King James has here "the Lord is on my side: I will not fear..."
The verse continues in the Latin quid faciat mihi homo, literally "what man might do to me"; the KJV finishes the verse "what can man do to me?"