Both atheists and theists live in faith. The two are really brethren in faith interpreting what they experience in certain ways, and then taking a leap of faith in commitment to that interpretation. Neither an atheist's nor a theist's worldview can be proven in the scientific sense, all we can do is assess things and then leap. To not leap at all is called agnosticism, which is to not choose an explanation of the world in which to invest yourself. But, I hold, we cannot function without beliefs and faith. Here I argue that total agnosticism is impossible, that we all live by faith, and because of that atheists and theists are closely tied siblings.
Whenever I sit on a chair I have faith that it will support me, when I ride my bike I have faith in the brakes, when I drop my backpack on the grass I have faith that it will not float up into the sky, when I feel like terrible and alone I have faith that God is there with me and that he cares for me.
"But" you object "the scientific method proves things beyond the shadow of a doubt."
"O contrare" says I "for the scientific community and scientific method are based on faith in the universe being an ordered, rational, consistent, repetitive, and predictable place. This foundation is a tradition that many take for granted, but ultimately this foundation is descended from belief in a good intelligent God who made the world and who can be depended upon to sustain it in such a way that the creatures within it can grow and live and prosper. Here is a hypothetical example. Let's re-discover gravity. We observe things falling and then with the scientific method we try and prove the "law of gravity." But to do so is simply to state either A or B (below) in faith:
A: (for a theist) God has seen fit for his creation to operate and function so that all mass in the universe attracts all other mass with a force inversely proportional to the distance squared and this seems to be something that is an integral, important part of how the universe functions, and thus something which we can rely on (if we believe in a God of order and stability) even though we do not fully understand it. We have much more discover and we must take our "laws" of science lightly, and we should not despair when they are violated, and we should not assume that all violations will be eventually explained with further "laws" for the universe is God's handy work and God makes no promises that we will understanding him, only that we we can trust and rely on him (for we are still existing aren't we).
B: (for an atheist) The world around me seems to function in a consistent way, yet I have no guarantee that it will continue to do so.
An atheist may commit to a "gravity" world view, saying "gravity is the constant, the foundation, the sustainer of all else" (which would be a commitment of faith that replaces God with gravity) but then as soon as the theory is violated, as soon as magnets are shown to violate gravitational theory, as soon as quantum theory gets in the way, then everything comes crashing down. There are always violations and exceptions and new discoveries, which at first seem to break all the rules. It is the true frontier scientists who live constantly in the realm of the unexplained, who operate always in faith, who make discoveries in moments of artistic inspiration, it is these men who understand that our science is not a monolith of tamed facts, but rather a herd of wild, beautiful theories which are in constant flux and transformation.
Science can dance and cry and cheer and spout out pretty colors and eloquent analysis, but it cannot answer the God question. To the theist science re-instills awe in the creator. To the atheist science instills awe in the unknown thing (not God) which is the source of the awesome universe that we find around us.
I like to think that their are certain things that our under my control, but I definitely know that their is much that is outside of my control. To have faith is to rely on that which is outside of my own control, and often it seems that our faith can be misplaced. The moment you have total faith in a partner the relationship goes bad for unexplainable reasons. The moment I sell my soul to the theory of relativity is the moment it is replaced by another theory. The moment I "know" exactly who and what God is and what his intentions in the world are is the exact moment that all I "know" is violated. Faith involves risk and uncertainty, as does life. In fact to live with a will is to choose actions, and this means putting faith in a great many things on a daily basis (from the soundness of a chair to the engineering genius that allows a controlled explosion to propel me down the street). Should we not then continually seek to put our faith in better and more trustworthy things, persons, and ideas. We cannot doubt everything for "to choose doubt as a philosophy of life is akin to choosing immobility as a means of transportation" (Life of Pi, 36). We all believe things and invest ourselves in those things.
What we should be concerned with is asking "What have I invested my life and identity in?" Whether or not we verbalize it most of us (myself included) have an obsession with our personal well-being, our possessions and our checking-account balance. But life must be about more then just these things, yet many people stop short of asking harder questions then "how can I be safe?", "how can me and mine be secure and prosperous?" But we must ask harder questions, we must seek out our underlying assumptions and verbalize them to ourselves. If we claim to be utterly undecided about a question such as "Is there a higher power to which I will be held accountable?" we should then examine our lifestyles and ask "given the way I am living what kind of unspoken answer to this question do I live out". To those who claim agnosticism in relation to whether God exists I say "do not fool yourself," if you seriously address the question "Does God Exist?" you will soon find your self committed one way or the other. Maybe it will take some self-reflection, but what could be more worthy a spending of time then to simply locate the flag you have already planted (and of course you may need to address what kind of God you believe does or does not exist as a part of this). Then from the firm ground of your own belief you can engage others and you participate in the joy of pursuing answers and applying your findings to your own life. If your answer is that "the God question is a pointless fruitless debate" then you probably already believe that there is no God, and if so then welcome to the club of faith.
We all have faith. Faith, a belief in and a reliance on something beyond our control, is where we start. To live is to embrace, foster, and test faith, and to seek a better understanding of that which we have faith in, so that we can be... well, more faithful to it.