Many people do not have the patience to wait for the result to happen.
They will pray for others or lay hands on someone and pray for healing or deliverance and then, when they do not see any immediate, outward change taking place, they will withdraw their faith and assume nothing has happened.
Next time you're tempted to evaluate what God is doing by the looks of things, do not do it. Remember instead that it is faith, not appearances, that makes miracles happen. It's the only real evidence that you need!
Hebrews 11:1(0107) 8 April 2007
Now faith is the substance of things hoped for, the evidence of things not seen.