I watched a video the other day about a girl who said "all this time, I had never invited God on my weight loss journey" and she decided that was what was missing. She then turned her life and weight around :)
I don't have faith, but I do believe that if you put your trust in what you know to be true, whether it's God, or yourself, you can do it! So good on you for knowing that with faith, you can succeed! :D