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.
Remember that it is faith, not appearances, that makes miracles happen.
Hebrews 11:1
Now faith is the substance of things hoped for, the evidence of things not seen.
(0751 30X2008)