Does God give you his Spirit and work miracles among you because you observe the law or because you believe what you heard?
Believing in the finished work of God, believing in the inheritance He has wrought for us on the cross, believing in who we are in Christ.. define the miracles or healings we are waiting for. If a person uses his/her effort to please God hoping to get miracles in return, then it is not believing but barter trading.
The enemy wants to stem the flow of miracles to us by seducing us back to the law(old covenant) so that we stay condemned.
Rejoice. There is now no condemnation for those who are in Christ Jesus. This is new covenant believing. Believe in Him who has already declared 2000 yrs ago : It is finished. Today it still stands finished...we cannot add anything more to His finished work! Continue to rest in His finished work and expect miracles to happen.