James 2:18, "Show me your faith apart from your works and I by my works will show you my faith." They go hand in hand. The more we trust God, the more we do in His name. The more we do in His name, the more we trust God. Each time our faith increases we become bolder and can do more in His name. It's a beautiful cycle. Each of us is in a diffeent place with the Lord, just like when Jesus was on earth. He had disciples who were close to Him and He had other followers on the periphery and others that were somewhere in between. There were times when the disciples were able to cast out demons and sickness and there were times when they were not able to. Jesus HImself could not perform many miracles in His hometown because of unbelief. Our faith in CHrist brings us salvation and deliverance only when we believe it. It's always there, we just have to believe it. Our faith in Christ brings us healing. It's always there, we just have to believe it. However, because we don't see many miracles today and because there is so much confusion in the church, we shouldn't be surprised that people aren't getting healed regularly. If we don't have unshakeable faith in basic teachings that clearly state which things are sin and which things are holy, it's to be expected that things like healing could get lost in the mix. We all just have to keep praying for God's mercy and ask for His guidance to lead our lives.
Faith in God is one thing... stupidity another.
Read history... even religious people during the middle ages (and that was a really christian era in Europe) did not live long and suffered from terrible afflictions. The great plauge they did see as a punishment from God when it was actually a disease carried by rats... but since they convinced everybode that it was Gods will noone was allowed to come with other explenations of the plauge.
And all of this led to that the church lost power. People reliased that the priest did not know what they were talking about when it came to diseases and that they should listen to "experts" (doctors, wise old women or nuns and monks that were pioneers in health care) that had no religious explanation but a real world explanation... such a simple thing such as keeping sick people and healty people apart because they realised that the plague spread between people and that it was a natural consequence of the disease and not an act of God.
Had the church in this time been supportive, helped people and not been stubborn and narrow minded they might have come out of it with higher regard... and not the downward slope that started after the plauge...
If you are on a sinking ship you don't stand still and pray to God... you runt to the life boat.