Jesus made an interesting comment in John 20:27, telling Thomas to "be not faithless, but believing". Thomas was bold in his denial that Christ had risen from the dead, until he actually was face to face with Jesus, again, in the verse 27 scenario. It's an interesting story about the way that we choose to believe, and the things in which we place our faith.
Despite how religious or irreligious a person is, or how they speak or act, each person has faith and places that faith in numerous things. The issue of whether they have faith specifically in God or His Christ is, in one sense, peripheral to the argument of whether all people exercise faith or not. I put it this way because I can recall several discussions with people who said that they did not have religious faith of any kind. Is that really possible?
What is religion, if not a set of rules and/or disciplines by which to conduct one's mental, practical, and spiritual affairs? If we were to rate the degree of effort that people place into the things that they do or the extent to which they will go to argue or defend an idea or belief, then we would be able to produce a quantitative analysis of these propositions.
Let's say that we set a 6 point scale. On that scale, zero is the choice to not answer the question. "5" would be the strongest affinity for the topic in question and "1" would represnt the least registerable affinity for the topic in question, with "3" being a teeter point at which the person would register either no opinion or no willingness to commit to either a strong or weak view of the topic. Let's make some sample questions.
The respondent would assign one number after each question: 0, 1, 2, 3, 4, 5:
I have faith in God.
I practice my faith.
I do not have faith in God.
I have faith in something.
I do not have faith in something.
I drive motorized vehicles.
I avoid all motorized vehicles.
I sit in chairs and climb ladders.
I try to avoid chairs and ladders.
I fly in aircraft.
I walk or drive on bridges.
I like unreliable results when I do things.
I like reliable results when I do things.
I usually choose to do things that are risky.
I usually avoid doing things that are risky.
I usually like to sit in chairs that will break.
I usually believe that chairs will break when I sit in them.
I like to ride in motor vehicles that are prone to crash.
I like to ride in aircraft that are prone to crash.
I usually avoid driving or walking across bridges.
I often avoid certain routes when traveling.
I always take the most direct route in my travels, regardless of safety.
As I'm sure you can see from the nature of the questions, whether the questions are staged negatively or positively, there is always an implication of faith no matter what we choose to do or not do in life. We pick and choose our events, activities, beliefs, and even our meals, based on what we know and what we hope, as compared with our experiences. So, the bottom line, without getting too heady about all this, is that we ask ourselves honestly in what or whom we are placing our faith regarding eternal things. Even the most avid atheist has a system of faith to which he/she clings and on which there is a strong dependency.
There was one conversation that sticks in my mind. I was talking with a guy about the Bible and Jesus Christ, and how God says we desperately need to make our peace with God through His only source of salvation, that being the sinless death, burial, and resurrection of Christ. Well, that fellow with whom I was discussing all this, pulled his wallet out of his pocket and emphatically waved it in my face saying, "This is my god! I don't need religion or God or Christ!" Well, he was right about one thing, his wallet and money were his gods. When I asked him what would happen and where he would turn when he ran out of money or he lost his wallet, he threatened me and turned away in disgust. As he left, I tried to politely say that the wallet and money weren't much of a god if they could be lost or exhausted by a mere human being. I think we all know quite clearly where that chap was potting his faith, even though he insisted that he had none.
In even more practical terms, a person sitting in a chair, either sat there ignorantly, based on past experience, or has deliberately chosen that one chair for a specific reason, including its perceived reliability. Have you ever moved to sit in a chair, but upon touching it decided to opt for a "less rickety" chair? That is combination of faith and experience in action. Experience tells you that rickety chairs are more prone to failure and faith tells you that your assessment of the probability is most likely correct. You cannot see if the chair would really hold you or if it would fail, but you act anyway, placing your faith and your keester in action to decide to and complete that action of sitting in the chair that you've chosen.