On what grounds can someone gain guardianship of my child?

My mother who is a Jehovah's Witness has temporary guardianship of my son and she is trying to gain Long Term Guardianship with the intent to adopt. I have a history of drug and alcohol use but I am Clean and Sober almost 10 months now. I want to get my son back from her and she is taking me to court saying that I am incapable of taking care of him. I am working, I have a place to live where he would have his own bedroom, I have a sponsor, i'm working the steps, I have a therapist, a Life Coach, I attend regular 12-step meetings and church weekly. I am heavily involved in my church and my mother is threatened by my religious beliefs because they are exact opposite of her Jehovah Witness beliefs ... She is hugging me and kissing me and telling me how proud she is of me, while at the same time stabbing me in the back and trying to take my child from me permanently. She let him stay with me for the weekend for Easter, so she must trust me some ... Does anyone have any experience with this matter? Our court case is going to be heard in Orange County Department L73.