Nowadays, "freethinkers" may have become a modern term for atheists but at the end of the day, these people pose some serious questions about belief systems, especially, spiritual kind.
Science as we know, is not superstitious and so it is easier to believe since it deals in facts and proofs.
But if we are to be honest with ourselves, we believe science not just because it provides proofs but, with those proofs come easier comprehension and understanding. Man is naturally afraid of what he cannot comprehend or control. FEAR is the answer, the problem, the issue; not lack of evidence/proof. Defeating fear with (mere) FAITH is almost impossible for any man. Mind you, faith and facts aren't the best of pals.
But of course, everyone should have his/her important role in life regardless of religion, race, gender, etc. Christianity is not like a social club which one joins just to show he is better than the other. Unfortunately, if we keep asking for "facts" the way we do, we may never find enough!

We allow ourselves to believe science. We Accept Science.
There may be fake medical practitioners, fake teachers even. But when it is really important, these cannot stop one from seeking medical assistance nor stop believing in science altogether. Beyond every other reason, it is also because we have less reservations against medicine. When you build up so much disbelief against anything/anyone, even when you see the real thing, the truth, you'd still doubt it; you'll be mainly interested in the dark spots (fake preachers).
One Needs a Free Spirit To Be Able To Accept Faith. It's not natural, not physical, nor scientific. It's Spiritual.

Lastly, Religion is basically man's effort to try and acknowledge, understand and/or appreciate the existence of supreme being. That is how these religions came to be. Those who failed to do so call themselves atheists. Christianity goes beyond religion when it is real and true.