There are the well-known evidences for the existence of God (there had to have been something that started it all), the idea that humans have an idea of a perfect being, and things like order and purpose in the universe. Those have great weight, but they don't PROVE God. Actually, nothing PROVES God, because God isn't provable like that. It's as if I said, "Prove that you love your partner." Well, you can give me evidences, but it's not something that can be proven, like science proves things. Science can "prove" the physical, but not the metaphysical. When I think about God, I can tell you what gives me evidence for his existence:

1. The created order. True science is limited to the scientific method, observation, and confirmation. Speculations backwards based on theories and agendas are, frankly, outside of the scope of true science, though that is not really what is being discussed here. To me the universe exhibits an order,complexity, and balance beyond the parameters possible in a system governed by pure chance. I see evidence of other forces at work that are necessary to make it even possible to generate what we see.

2. Purpose. While science and my five senses can tell me what is there and how it works, it cannot explain the area of purpose that my observations tell me is universal to humanity. We all have a sense of purpose, a desire for purpose, and a quest for meaning that to me is evidence of a foundation in the universe consistent with the existence of a divine being, and inconsistent with the limitations of a closed system of random coincidences regulated by natural processes.

3. Consistency. My study of Scripture finds in the Bible a credible explanation of humanity that anyone is able to observe with their five senses, reliably discussing hundreds of subjects pertinent to humanity (good, evil, purpose, history, depravity, joy, blessing, health, disease, et al.) with depth, breadth, and understanding. I find in the quality of the thoughts in the writing an intellect beyond the capacity of humanity, given that the writing took place over a 1300-year span by over 40 authors from numerous locations. I see there evidence that to me in convincing of a common source, despite the varieties of personalities and writing styles incorporated therein.

4. Lifechange. I have seen lives changed in ways far different from those excited about political processes, motivated by exciting business opportunities, transformed by relationships, or enlightened by ideas. The changes I have seen in individuals give evidence that they have been acted upon by a spiritual power of a life-giving nature, and those changes encompass a complete metamorphosis of attitudes, thoughts, desires, and actions.

So maybe that helps. When we get to "how sure are you about something," that's a great discussion. Generally we know things by observations and interaction with our five senses, plus reason, plus testimony of reliable witnesses, plus our intuitions. When those elements line up, we say we "know" something. It's a judgment call, though, because sometimes our senses deceive us, we have faulty reasoning, we hear false testimony, or our intuitions mislead us. So we do our best: (1) Does it correspond to reality as best I can evaluate it? (2) is it consistent in the world and according to reason?, and (3) does it work? If we're coming up thumbs up pretty much all around, we say we "know" something.

But what about prayer, since you asked? Prayer is greatly misunderstood in the Bible by us. This is going to be tough to explain in a short post. A careful study of the Bible shows that prayer hardly EVER changes people's circumstances (though on occasion it did). Almost every reference to prayer in the Bible has to do with people's INNER lives—their spiritual lives. God is far more concerned about the heart than about good luck. So when people pray for "stuff" and they don't get it, they go, "Dude, see, there's no God." Well duh. Somebody ain't readin' carefully enough, but we're all too quick to throw in the towel and walk away bitter. This is a MUCH larger conversation, because I'll bet lots more questions are popping into your head.

How can we be sure there's a heaven? One guy 2000 years came back and told us about it. He said, "You're just going to have to believe me on this one, and since I just came back from the dead, that should give me some credibility on it." So, we're back to the previous question of "how sure you are about something". It's a matter of the weight of evidence, in all of these areas. Talk back to me as you wish. I'm gonna press the "save" button now...

OK, I love most of your answer. You're right, everything I say I know about, say, science (I love science) is, now that I think it this way, just faith based on what I've studied and what I've experienced. (Even then, when I was sure of god, it was because of previous evidence, not just by the book).

But what about God? I know there's this book, and the guy who speaks at the church/temple/whatever and your parents told you that the book is enough evidence about his existence. But is it really? Or have you experienced any other evidence for his existence? (as pointed out above, I did, though maybe I misunderstood it a little).

Could we then talk about how sure you are about something? For instance, if 5 min ago my door was working fine, and nothing catastrophic has happened to it, and with my own eyes I can see that it looks to be intact, I can be 95% sure that If I open that doorknob it will open. I am 90% sure that when I click on this save button all this text will be published online. But what if I pray for good luck? How sure can I be that God will listen to me? How sure can we all be there's a Heaven, since no one who has died has in 2000 years come back to tell us there is one?

Yay! The save button did work!

Thanks for the reply. We obviously have different definitions of faith. I happen to think (obviously) that your definition of "faith is the absence of evidence" is wildly inaccurate. A silly example (nowhere near the level of Hume, of course): Indiana Jones and the Last Crusade. In one of the final scenes, Indy is ready to step off a cliff, the proverbial "blind leap of faith." And yet it's not at all. He has his father's book. He's been reading from the book for awhile now and finding it to be reliable, step after step. The mystery is still there, but so have been rewards of knowledge and progress. His faith to "make the leap" is based on belief, for sure, in his father's character and reliability, and the learned truthfulness of the book.

Of course you can have faith in silly stuff. That doesn't denigrate the deeper meaning and application. Some people vote for Mickey Mouse for president, but that doesn't bring a fall to democracy and its ideals.

Possibly another flaw in your definition of faith is our modern conception of existence. In the realm of science we make flat statements that the world exists, and yet the same person might say they believe God exists. Why should we use different wording? It goes back to a principle of authority. Our view of science as an authority causes us to talk about material things as existence, but non-material things as simply our opinions or beliefs. I would contend, in contrast, that the moral law within us exists just as surely as the stars in the heavens (reflecting with Kant). We can also approach this with regard to time. Time also has places, and in time we have distinct events that each has its own purpose. Special events have no homogeneity—each is unique as it exists in a moment in time. In space and time the distinctive places that exist are identified in relative terms—they all exist relative to the person. In time, you cannot speak about the present unless there is a subject who says NOW. So, in the same way, time is relative to us. Present, past and future do not exist in physics; they exist in our experience only in relation to us. Heaven, earth and time all have a religious sense and a personal sense—and that is why they really exist. Faith is not the absence of evidence, by any means. Principles of physics are delimited for the sake of objectivity. It cannot and does not cover the whole of reality. Metaphysics have always existed alongside of physics and are needed to fill in the totality of reality. To claim that the structural analysis of the chair is real, but religious faith is not is to ignore metaphysical realities.

Faith does not rely on evidence, a belief relies on both evidence and faith. Faith is the absence of evidence. For one to believe in something, either the evidence needs to be great, or the faith does. Faith is not founded by evidence, it is required due to the lack of evidence.

With respect to the scenarios you put forth, you point out to things like the structural ability of a chair. It is very easy to acquire evidence to support a belief that a chair will support your weight, so the amount of faith required to formally complete the belief is small. However, religious beliefs rely on little evidence, so require a lot of faith. If you are genuinely trying to compare religious beliefs to that of the structural ability of a chair, I question your understanding of what sufficient evidence is.

You say "Faith is always defendable with logic." What? I can have faith is silly stuff, it is not a requirement of faith that it is logically valid or sound. This whole argument is taking Hume's rejection of induction at a very superficial level; you may need to rethink the fact you equate certainty of easily testable phenomena and certainty in old texts that were mostly accumulated from verbal stories of events that happened generations before the transcriptions were made.

Sure, but you're operating in a closed system of pure physics without giving an consideration to metaphysics. Do non-material things have existence? Law. Justice. Peace. Love. Do non-material things have authority? Again, law. Love. Mercy. Morality. Conscience. Kant would contend that the moral law within us exists just as much as a chair with structural integrity. Space is filled with places that have a particular purpose, and therefore they exist. They are impregnated with meaning that differentiates each place from the other. Don't be quick to blow off my comparison as "poor". There is material homogeneity (atoms, molecules, "chairs"), but because there is no homogeneity of purpose we say the metaphysical doesn't exist, and therefore religious faith is not as real as a chair. What about time? Does time exist? It has no structure integrity, but only metaphysical existence. But you BELIEVE in it and live by it. Past, present, and future don't exist in physics, but only in relation to US as the experimenters of physics. Earth and time have a personal, metaphysical sense in relation to us, and they EXIST. Physics cannot and does not cover the whole of reality.

I've never understood how people could compare religious faith to trust in structural integrity. Do you understand that/why many of us find this comparison to be very poor?

To me, faith is an assumption of truth based on the evidence (and faith is always based on evidence) that makes it reasonable to make that assumption. When I go to sit in a chair, I can't be sure that it will hold me, since chairs do, on occasion, break. But I've sat in hundreds of chairs, and I've sat in this one dozens of times, so I have faith enough to plant my butt down without doing a study on it, though even a study wouldn't guarantee solidness. I make an assumption of truth (the chair will hold me) based on enough evidence (chairs hold people, and this one has held me before) to make it reasonable to make that assumption. So also when I reach out to turn a doorknob. I turn it and walk, believing that the door will open, as doors do, and I can walk through. I can't know for sure that it will, but I have faith: a logical assumption of truth based on evidence. So also when I put my key in the car to start it, or pull a cord to start a lawnmower, or ANYTHING. it's all faith, because I can't know the future. Sometimes mowers don't start and doors don't open, but I proceed on the logical assumption of truth based on previous evidence. That's what faith is. In the Bible, people believed AFTER there was enough evidence to create a basis of a logical assumption of truth based on enough evidence. People didn't show FAITH in Jesus until he had initiated some miracles. Then they started lining up for him to heal them, because now there was something to go on. It was still faith, because it's future and hence (at least temporarily) unknowable. That's how I see it. Faith is always defendable with logic. There's no silliness about it. And there is a mountain of certainty, but certainty tempered by an ignorance of future characteristic of everything we do. All of us live our lives by faith. We go to the store, assuming it's still there. We pick up our phones, believing they'll work and actually connect us to the person we're after. We're surprised if they don't give us the person we're after, because we are so used to our faith achieving its logical end. You can't be 100% certain you'll be alive tomorrow, but you make plans. You can't be 100% certain your car will start, but you walk to it, get in, and turn the key. A person can be as certain about God as about anything else, because there is an assumption of truth based on the evidence that makes it reasonable to make that assumption.

For quite a while I was very close to God (who was very similar to what Catholics and Christians say, but not quite). I was very happy and comfortable, but every time I was asked, I made sure I made the point clear that I did not believe in him, but I was certain he was with me, because I felt him with me, and the good luck / prayers ratio was too high. I had full trust in MY God some years ago (though it was most probably not everyone's God), but now I'm an atheist.

Anyway, are you a believer? What keeps you from being sure? How far are you willing to take your life in the direction of something you are not 100% sure of?