morphene
Sort of- one step prior to that, although as a side I do agree with the statement you've made.
Basically that there is no set of coherent experiences that we can have that do not have some kind of cause that can be understood (intelligible). The cause (the underlying principle) may explain the set of experiences, but does not explain itself, e.g.: evolution as a principle of change explains the motion from single cell organisms to the vast and complex array of biological life, but it does not explain why evolution should be the case at all. That is: it explains changes in biological organisms (that they move towards the most efficient reproducing systems they can/survival of the fittest) but it does not explain why things should want to survive in the first place.
The explanation for this may well be found in chemistry, which may well have its explanation in physics, and so on and so on. In each step what we are doing is uncovering yet another principle which in turn requires a principle itself to be explained.
But an infinite regress is not possible- it would mean there is no origin, and if there is no origin how could the causal chain have begun?
Further, even if we assume that there is an infinite regress, which explains all natural principles, it fails to explain why there should even be an infinite regress- that is, no natural principle (even infinite regress) is self-sufficient.
Therefore it is plausible and reasonable to suppose that there IS a self-sufficient principle that exists, outside of, but as the first cause of the natural order. It is by no means a given, and while some may not find it convincing, I hope that I've shown it is at least rational to suppose that there is a God who is the self-sufficient cause of the natural order.
As for whether or not this is enough to ensure cordial conversation then I think so, yes. If you don't think that belief in God is fundamentally irrational, then you are unlikely to say anything that drastically offensive and you should be able to be normal and friendly, and let it all hang out. Believing in God or not doesn't vastly change people's natures. I'm sure their lives are remarkably similar to yours.