What would it take to lose your faith?

DavidMarshall recently had an abortive exchange with militant atheist PeterBoghossian:
http://christthetao.blogspot.com/2012/09/peter-boghossian-sees-through-me.html
Boghossian’s attitude isirrational. He acts as if it’s useless to debate someone unless your opponentis open to persuasion. But public debates aren’t about convincing youropponent. Marshall is a published Christian apologist who’s debated otheratheists. Assuming, for the sake of argument, that Marshall is a fideist, ifBoghossian had debated him and demonstrated that Marshall’s faith isirrational, that would be a notch in Boghossian’s belt.
Be that as it may, I’d liketo address Boghossian’s challenge. He said:
Answer this question: Whatwould it take for you to lose your faith?
This does not answer thequestion. Please answer the question or this will be our lastcommunication.  What reasons wouldhave to be mistaken? Give me an example of a reason and how you know it wouldbe mistaken. What would this look like?
But that’s a deceptivelysimple question.
i) For one thing, professingChristians can lose their faith for emotional reasons rather than intellectualreasons. Disappointment is a common factor.
ii) Presumably, Boghossian’sis getting at the issue of whether Christian faith is falsifiable. And there’sa sense in which, hypothetically speaking, Christianity must be falsifiable.Christianity can’t be true and still be made consistent with just anything.Christianity is not constantly redefinable. If Christianity is true, then someother things are false. And if some other things are true, then Christianity isfalse. For instance, if Islam were true, that would falsify Christianity.
iii) Also, from a Reformedstandpoint, faith is something only God can give, and something which, by thesame token, God can take away.
iv) However, some beliefs aremore far-reaching than others. Let’s alter Boghossian’s question:
What would it take for you tocease believing in other minds or the external world?
Now that’s not a question whichis easy to answer. Indeed, the question may be unanswerable. That’s becausebelief in other minds or the external world are beliefs by which we evaluateother beliefs. But if you ask me to consider what reality is like assuming thatmy friends, parents, siblings, spouse, and kids are computer simulations, thatmy memories are implanted, then that’s a question I can’t answer, for at thatpoint I have lost any frame of reference. I have nothing left to go on.
v) Perhaps Boghossian wouldsay that’s an extreme case, which is hardly analogous to losing your Christianfaith. But is it? Actually, a godless world is even more reductionistic thanthe scenario I just outlined. Consider some implications of the Christianfaith:
a) Our minds, memories, andsenses are trustworthy in performing what God designed them to do.
b) There’s objectivemorality.
c) There’s a good reason foreverything that happens.
But suppose you denyChristianity, and thereby deny those implications. If you go down that road,you begin to lose your bearings. You can’t find your way back. Deny (a-c), andwhat’s left? What’s your standard of comparison? 
vi) Which brings me back to(ii). Hypothetically speaking, Christianity is falsifiable. Yet evenfalsification takes certain truth-conditions for granted. But what if denyingChristianity ends up denying the ability to evaluate anything?
Boghossian’s question issuperficial. It fails to take the alternative into account.