Chat: You are incapable of believing God for anything, including healing.
I beg to differ. You just told me that you believe that Jesus Christ is alive, even though I assume that you have never seen Him in person. I think the devil has discouraged you into thinking that you are a total failure as far as faith is concerned, but that cannot be the case. You already believe the most important thing anyone could believe – that Jesus rose physically from the dead. You may not have exercised your faith in the area of healing yet – but you certainly ARE capable of exercising faith because you are doing it right now in regard to your eternal salvation!
You should read You Have Faith next.