Respectfully, I'm having trouble with the premise in some of the things you are saying. For example, I would not consider speaking to a congregation as being in the same context of witnessing door to door. While I definitely wouldn't begin the Gospel by expressing some doubts. However in a congregation of supposed believers, honesty might compel me to say I am not sure about some particular intricacies that may arise in deeper elaboration.
Again, the premise you construct this upon is somewhat suspect. I gather that you would like to establish equal footing to begin with, and I suppose that might be useful to ease any anxiety stemming from vanity.
I think we clearly aren't communicating, because I likewise am not following much of what you're saying. I'm not saying this in a critical way. It just seems to me we're talking about apples and oranges.
I'm talking about the bottom-line questions:
Does God exist?
If God exists, is He the God of Christianity?
I cannot imagine addressing any congregation and beginning "Putting aside the fact we may all harbor a modicum of doubt as to whether God exists at all, let's turn to the Gospel of John." It sounds to me as though what you must be talking about are specific verses and doctrines where there are legitimate differences of opinion among Christian theologians, scholars, leaders and believers.
No, I'm not merely talking about "easing any anxiety stemming from vanity." I'm talking about a Christian honestly admitting he cannot actually know, in any sense that is going to be intelligible or meaningful to an atheist, that God exists or Christianity is true. I'm talking about an atheist honestly admitting he cannot know, in any sense that is going to be intelligible or meaningful to a Christian, that God doesn't exist or Christianity isn't true.
The Christian and the atheist have each become convinced a particular paradigm is true. Each paradigm carries with it a host of "truths" that must be accepted as axiomatic or the paradigm collapses. "There is no God" is axiomatic for an atheist but not for a Christian. Once the Christian and the atheist admit this reality, they can then have an intelligent and respectful discussion as to why each believes the way he does - and perhaps one can convince the other that his paradigm is at least worthy of consideration. The discussion will be easier with a Hindu or Muslim, of course, because both of their paradigms are at least theistic.
But I don't actually believe that I don't absolutely know the Truth of what I'm saying, and therefore also don't believe that I can't demonstrate it the same way as whether my Ford is sitting in my driveway. I feel it goes unappreciated when I say that the definition of the term God is going to be the issue. Any serious discussion must begin there. If I accept their term as equally valid, then all terms will change in meaning from the God that I know. Faith will not be faith, but rather degrees of faith and unfaith, conviction will not be conviction but rather delusion or illusion, Light won't be Light and darkness will not be darkness, but rather shades of gray.
I would simply disagree with the first sentence. The atheist and I agree Fords exist. To demonstrate whether mine is in my garage, I simply open the door and say "There's my Ford and here's my title." For someone holding the naturalistic/materialistic/atheistic paradigm, however, it is an axiom that there is no God of any sort - not just no God of Christianity, but no God of any sort. The atheist doesn't care how you define God unless you're willing to define Him as "Non-existent." So in what way analogous to demonstrating your Ford is in your garage would you demonstrate the reality of God to an atheist? You can't. You can only convince him your Christian paradigm isn't the silliness he always assumed it was and hope he'll give it serious consideration and discover for himself, with the help of the Holy Spirit, what you've discovered.
Respectfully, I feel that there must be a premise that is suspect, because of what you are saying. I would not say or think any of this. To me, how you are defining faith comes into question. Faith must be applied to that which is hoped for, or it's not faith. It can't be applied to what is dreaded and yet be called faith. Why? Because we are ultimately believing that God is the definer of what is good and evil. Hence God is Light and without darkness.
Where in my post do you find a definition of faith? Where in my post do you see any suggestion of dread on my part?
In the sense in which you're talking of faith, I'd say what I've always said: My faith is my conviction Christianity is true and my decision to live as though it were true, while acknowledging some slight possibility it might not be. I wouldn't live as though Christianity were true unless I had reached a strong conviction it was. To live as though it were true while having no such conviction would be schizophrenic. My conviction Christianity is true brings me peace and joy. The slight possibility it might not be true causes me no dread. If it's not true, in fact, I'd like to know this at the earliest possible date.
Your confidence and mine, is tested in this world, but it doesn't change the criteria of what constitutes that which we strive to have confidence in. I'd like to comment on this example from scripture. The terms "believe" and help my "unbelief" are both predicated on the same essential acknowledgment that the object faith or unfaith must be hoped in for faith to remain coherent.
"Confidence" is not, of course, absolute knowledge. When I'm vacationing in Hawaii, I can be confident my Ford is still sitting in my locked garage in Arizona. But I won't have absolute knowledge until I return home and look. I don't believe I'll have this level of certainty about Christianity this side of the Second Coming.
I have a high level of confidence Christianity is true. Because I've pondered and lived my beliefs over many years, there isn't much that occurs that really tests them anymore. The definitive, no-question-about-it discovery of Jesus' skeleton? Yes, that would test them in a big way.
When the father of the possessed child says "I believe, help my unbelief," he is honestly saying (I believe) that his belief is genuine but not free from all doubt. Jesus says if we had the faith of a mustard seed we could order mountains to jump into the sea - but no one yet has been able to do this. Why? Why can't you do this, or at least a minor-league version of it, if you have the level of certainty you are describing? If we're honest, it's because we all harbor some modicum of doubt, small as it might be; in our day-to-day lives, we all hedge our bets to some extent.
I think the bottom line is precisely what was suggested in Papa Zoom's first post: "I know" really means "I've become very, very convinced." But sincere atheists, Muslims and Hindus have likewise become very, very convinced. There is no way around this except to explain why you have become very convinced and hope they too will become very convinced of what you are very convinced about rather than of what they are currently very convinced about. But none of us really "knows," and I for one have no difficulty admitting this fact.
I think I've now beaten to death whatever I can contribute to the "knowing" discussion and should take my apples to a different thread.