My exchanges with Christians illustrate well enough that Christians aren't serious when discussing questions of faith. Why do I say such a thing? Christians certainly feel themselves to be serious, more serious than any mere unbeliever could ever imagine because they, and they alone, know what is truly at stake. Yada yada yada about eternal torment, Judgment Day, etc.
A Christian is not serious when discussing his faith, because (s)he is a Christian first and a seeker of truth and wholeness of mind second. A Christian expects his listeners to put themselves at risk of changing their beliefs while not putting their own beliefs at risk as well.
Consequently, for anyone valuing inquiry that is not adverse to the risks and dangers of actually discovering something unexpected, discourse with a Christian is mostly a waste of time. I say "mostly" only because there is some value to investigating the intellectual and spiritual acrobatics to which Christians subject themselves. That is if one has a taste for dramedy [drama + comedy].
Incidentally, I make an exception for my more mischievous moods. I have been known to play with Christians in proselytizing mode. They're not going to change their minds, so why should I bother to make-believe that they might? Or treat anything that they might say as being on a higher level than anything a used-car salesman might say?
Just to be clear, I will on occasion use Christian proselytizers to remind myself of how clever I can sometimes be. And more than once I, atheist that I am, had to help Christians bear witness to Christ and help them explain the Gospel and point them to Bible passages that fit better than the ones they were using. I felt really good about myself afterwards. If that isn't a good deed, then what is?
This attitude might strike some as "fanatical," well it's not. But these are usually the same people who aren't used thinking very hard about anything. A Christian has much (or little) integrity of opinion and intellect as a used car salesman. They're both trying to sell something and neither can be trusted for that reason. They'll do and say just about anything to close the deal.
Both have a strong personal interests in persuading their listeners. A Christian's opinions form the basis of his social life and often livelihood. And those of us who have suffered the loss of friends and so-called "brothers and sisters in Christ," not too mention love, respect, and even contact with family, because of unwisely voiced doubts know exactly what I mean.
Ostracism is a powerful weapon in the arsenal of faith. It may well be the most powerful.