Faith and belief, in the Christian sense, are not synonyms. You can believe in something but have no faith in it. Faith is closer to the word trust.
This is particularly true for faith in God. Sometimes we think that if only we believed in God *enough* we could see the things he promised. We screw ourselves up and try to believe real hard, and still we're weak.
God wants to heal people. to bring his life and power in his church, all the things we hope and dream of and plenty more. But to actually have faith, that trust and connection to God that makes these things happen, requires more than belief. It requires being close enough to the heart of God to *be able* to step out in faith. The power of God in us is for *us* to be able to do things, not just for us to have the faith that he'll do them. That means a closeness to him that enable us to have the power and life, and *we* do them. Or at least him through us. We're to be filled with the Holy Spirit and move in his life and power, not to wave our hands and hope that he does it.
That requires much more depth and purer hearts, a deeper reality of knowing God and his life than we've had before. Getting there is a journey, a process. "Ever increasing faith". If you're on the path then each next step is small, achievable. But if you're not getting deeper and closer, just wishing that you were, then it seems an impossible dream and you screw yourself up trying to believe even more. Or you give up and decide that this is as good as it gets and we just have to live with it.
So how do we get there? Well, Jesus said "seek and you will find". Do you believe that, are you ready to trust your life to it, are you really willing to seek? It takes everything though. Bend your whole life, passion, will, substance into searching for that life and power. Be dissatisfied with what you have from God and demand more. That passion can become a life consuming fire. The more of the fire you taste the hungrier you'll get for more.
A practical consequence of this is how we treat doubt. If
we're "trying to believe as hard as we can" then doubt is the enemy and
we push it away. The trouble is that you're rejecting and pushing away
the parts of yourself that aren't yet able to trust. A house divided against itself can't stand. Instead we need to cry “I believe; help my unbelief!”. We need to be honest with ourselves and with God about who we are, we need to bring our doubts to God, with a mind and heart open to faith of course, and ask for him to bring us into a place of faith. And getting there is a journey of many steps.
As Christians we can believe that we're called to blind faith. To step out in the dark, "off a cliff", and believe that God will meet our faith. We feel guilty for not doing it more, not trusting in God. Yet when we do it we often hit the ground, and that hurts, which is why we don't want to do it! And then we feel more guilty, and try to screw ourselves up to have the belief to step off the next cliff. Stepping off cliffs and hitting the ground is painful and discouraging. Sometimes God wants that, but in my experience you know it when it happens.
Jesus promised to be a lamp to our feet. We may not be able to see very far down the road, but we can see the next step. God doesn't want us to feel discouraged and guilty, and he isn't calling us to jump off every cliff we see! It's a journey of ever increasing faith, made up of small steps in the light. Yes there is more we could be doing, but your job is not to look at the mountain you haven't yet climbed but to see the next step you need to make. That still takes a step of faith, but it isn't a leap in the dark.