Epistemology keeps rearing its head on threads on which I participate. This is the branch of philosophy dealing with knowledge - what knowledge is and what it means to claim we "know" something.
I keep being told I say things that don't sound very Christian. I keep responding, "This is a matter of epistemology." So here we are.
To claim we have knowledge, we must have some legitimate basis for the claim. A legitimate basis is called justification or warrant. (As we'll discuss, knowledge requires more than mere justification, but it does require that.)
Famed Christian epistemologist Alvin Plantinga says Christians can claim to have justification for their beliefs without any evidence whatsoever. He says we can claim to have justification on the basis of our internal sensus divinitatis (sense of the divine) and the internal witness of the Holy Spirit.
However, even Plantinga agrees this doesn't mean Christian belief is true, merely that it isn't irrational. "Justified" basically means "not irrational." It doesn't mean "true."
How do we determine if Christianity is true - or can we?
I believe there are threshold truth questions: Is naturalism true? If it is, there is no god. If it isn't, there may be a god of some sort. (Not all atheism is naturalistic - many atheists believe in life after death and some sort of spiritual realm.)
If we decide naturalism isn't true, which ism is then most likely to be true - non-naturalistic atheism, deism or theism? If we decide it's theism, which version of theism? (Christianity, of course, is a species of theism.)
These are all ultimate metaphysical questions. As a finite human being, I'm like a goldfish in a bowl trying to explain the reality outside the room in which the bowl is located. I can never really know to a 100% objective certainty whether naturalism is true or false, theism is true or false, or Christianity is true or false. I can only reach a level of conviction on these matters.
On each of these matters, I believe we reach a level of conviction through experience, observation, study, reflection and intuition. At some point, we reach a level of conviction naturalism is false, theism is true, and Christianity is true. We have a rational, well-justified, defensible conviction. The more diligent our quest, the more solid our convictions will be.
(Obviously, few people address these matters in a tidy order. It's usually more of a jumbled mess, but we do reach convictions on the critical questions.)
Christianity, of course, also includes the notion of revelation by God - in the Bible, in the person of Jesus, in the indwelling of the Spirit. However, I only believe and experience these things as revelations by God after I've reached a conviction Christianity is true. They may strongly reinforce my conviction to the point where I claim to "know" Christianity is true, but a Jew, Muslim or Hindu can make the same sorts of claims and so we're really still talking about a very strong conviction rather than knowledge.
This being the case, I never claim more for my Christian beliefs than I rationally can. I don't play the "pretend certainty" game, even though I've had a startling born-again experience, several other paranormal experiences, and several complex life events I can only attribute to the hand of God. Convincing as they were to me, they all might be explained in other ways - including defects in my own thinking and perceptions. (Significantly, even Plantinga admits his epistemology only works with properly functioning mental faculties.)
Honesty compels me to admit that, remote as the possibility may seem to me, naturalistic atheism, Buddhism or Hinduism might be true. Lots of very intelligent people who have engaged in diligent quests believe these things.
Honesty also compels me to admit my mainstream understanding of Christianity might be only 73% or 48% true.
I thus don't claim any more for my Christian beliefs than conviction. I try to live as though they were true while accepting they might not be. I examine and question them continually, both because it's enjoyable and because my goal is to get as close to metaphysical Truth as I can in this lifetime. I don't think there is anything irreligious or un-Christian about this.
So that's my notion of epistemology.
Many Christians, like other believers, were indoctrinated into their beliefs as children. Many Christians, like other believers, hold their beliefs mostly on the basis of cultural conditioning. Others went directly to Christianity as the result of a single mystical experience of some sort. Perhaps they simple heard the Gospel and had an "A-ha!" moment inspired by the Holy Spirit. Many of these folks have never examined or questioned their beliefs. This doesn't mean they "aren't real Christians" or are somehow "lesser Christians." Many do claim "knowledge" or "certainty" they don't really have - not in any epistemic sense anyway - because they're afraid to confront what they actually do believe and why. That's fine - when they question my Christianity, I realize it's mostly just a defense mechanism.
The traditional formulation in philosophy is, KNOWLEDGE = JUSTIFIED TRUE BELIEF. With metaphysical belief systems like Christianity, it's the "TRUE" requirement that's the problem. As Christians, I believe, we have JUSTIFIED CONVICTIONS.
Feel free to convince me I'm wrong.