One of the most galling tendencies of Religionists is the constant conflation of Atheists belief in science with the Religionists belief in revealed knowledge and faith in God. Religionists claim that Atheists actually engage in 'Scientism,' that we have elevated science to a religion, that we have 'Faith' in science and that therefore we are just as guilty as they are of belief, that their belief in God is no different than our belief in science.
This proposition could not possibly be more misguided and wrong. As a threshold matter, Science and Faith are not remotely similar. Faith, as I have discussed here and here is a belief in an unrealized proposition despite the complete absence of any evidence to support belief in said proposition or despite abundant evidence in opposition to said proposition. Faith is, by its very nature, irrational, because if one had a rational evidentiary basis to believe, Faith would be ipso facto unnecessary.
Science, on the other hand, is a TOOL, a METHOD by which the truth of falsity of an unrealized proposition (a hypothesis) can be analyzed, studied, replicated, accepted or rejected. Science is not a BELIEF
in anything at all, it is merely a means of analyzing whether a belief is valid. The only way in which science and Faith even intersect is that science can be used to as a tool to measure the evidentiary basis for an unrealized proposition thereby rendering a specific proposition as either a matter of reasoned belief, or a matter of faith. Science merely serves as a marker between which unrealized propositions are a matter of reasoned understanding and those which are not.
To illustrate, let us take the example of Noah's Ark. The truth or falsity of the tale of Noah's Ark is a hypothesis. Indeed, the truth or falsity of the tale of Noah's Ark is a testable hypothesis in that a worldwide flood 6000 to 8000 years ago would have left incredibly vivid signs in the geological record. It is a testable hypothesis in that we have the measurements of the vessel and can make calculations of the amount of space needed to house every species on Earth, the amount of food needed to sustain them, the amount of waste generated by the volume of animals, the amount of work necessary for the crew to feed and dispose of waste. We can bring the tools of science to bear on the truth or falsity of the tale of Noah's Ark, just as we can for every other Religionist claim.
When one does this, the tale of Noah's Ark clearly cannot fall within the realm of reasoned belief because 1) There is no geological evidence whatsoever to support the idea of a worldwide flood. 2) The dimensions of the Ark given in the Bible are barely enough to house the tiniest fraction of the species on Earth or even the species indigenous to the Middle East, even setting aside questions of how they would have gotten species from Europe, Asia, North America, Australia, etc. 3) The amount of food necessary to feed the biomass the Ark would hold for 40 days would have filled numerous other Arks. 4) The amount of waste generated by the biomass aboard the Ark would have taken hundreds of hours a day to remove. Nothing about the tale of Noah's Ark comports with any of the geological, biological, paleontological, physical or mathematical understanding of the Universe. Therefore the tale of Noah's Ark MUST fall outside the realm of rational belief. To say that Noah's Ark is a rational belief is utterly false.
One can still CHOOSE to believe in the truth of the tale of Noah's Ark, but their belief is irrational, and requires Faith because ALL available evidence militates against its truth. It requires that one assume things like dimensional pockets within the ark to house the animals, or disintegration and de-atomization of feces, or divine rearrangement of the geological record to hide all geological record of the Flood. Once can still have Faith and one can still CHOOSE to believe, but that belief has no basis in rationality, no basis in evidence, no basis in fact. Science is merely the TOOL by which we can draw that line.
Religionists often argue that atheists have Faith in Science, that we have Faith that our senses tell us accurate things about the Universe, that we have Faith that Science can tell us true things about the Universe. Again, while it is philosophically possible that our every sensory input is false, that our every understanding is flawed, that our perceptions, thoughts, feelings, experiences are in fact a delusion and that the Universe is vastly different than we perceive, such a belief still obtains nothing for the proponent of Faith, because if such a scenario is actually true, then their Faith is equally subject to our misguided perceptions.
Setting aside that useless argument, one is left with the simple fact that if indeed our senses do tell us things that are true or truish about the Universe, then using those senses to determine whether an unrealized proposition is established or refuted by the evidence is the most rational course of action. This is the ENTIRE basis of science. This is precisely what distinguishes science from Faith. Science is merely a tool for establishing the plausibility, truth, or falisty of unrealized propositions, not a belief IN them. Faith is the exact opposite.
God's existence is an unrealized proposition in which a great number of people believe place their Faith. Science is a method by which our senses can be used to attempt to understand the Universe and the world around us, not a belief. Only if one assumes that our every sensory input is irreparably flawed can Science be said to be on an equal footing with Faith. And such a belief is utterly useless in any practical sense as it renders all belief in ANYTHING completely suspect.