Let me give you the best definition of faith I've ever heard. It goes like this: Faith is belief plus unbelief and acting on the belief part.
We all know that belief is involved in faith. If you go to a doctor, you must believe he can help you. If you don't believe that, you'll never go in the first place. Before you step into an elevator, you've got to believe it will hold you up. If you don't believe it, you'll end up taking the stairs. Belief is always the first part of faith. It is the conviction that certain things are true.
Unfortunately some people stop their definition of faith right there. They think faith is belief plus nothing else. Faith to them is pure belief without any mixture of doubt. That's okay as long as you stay in your house, in your bed, and under the covers. But in this world, it's hard to arrive at 100% certainty about anything. You hope the doctor can help you, but he might make a mistake. You hope the elevator will hold you up, but maybe the cable is frayed.
People who truly believe that faith means 100% certainty are paralyzed. They are waiting for something that will never happen. In truth, unbelief is always mixed in with our belief. You see it best in the big decisions of life. You get a good job offer in another part of the country. It's a great opportunity, but you don't want to move. You are stuck in your present job, but the kids are happy in school. Your wife doesn't want to move, but you've found twice the house for half the money. You think you should move, but some of your friends aren’t sure. Late at night you lie awake tossing and turning, first going one way and then going another.
That's reality. You don't have 100% certainty and you don’t know of any way to get 100% certainty. You think so, you hope so, you pray for guidance, you seek counsel, you write it all down, you wait for a lightning bolt from heaven but it never comes.
What is true biblical faith? In the big decisions of life, faith is not waiting for 100% certainty. Faith is wavering between belief and unbelief, doubt and assurance, hope and despair, and finally, hesitantly, with your heart in your hands, acting on the belief part.
Living by faith means taking a step forward, however small, however halting, however unsure of yourself you may be. Like Abraham of old, you may be called to obey God without knowing where you are going (Hebrews 11:8). What step do you need to take this week? Do it, and let God take care of what happens next.