Does challenging one's faith undermine it?  Some would say so, others would say not.  During the atheist discussion group which I attend once a month, I made the point that I would rather see a person of faith challenged on what she believes, to be forced to work through why she believes what she believes, rather than live her life without really thinking about why she has faith.  That is one reason why, I added, I attend the group, to dialogue with and explore the other side.  We can often learn significant things from views with which we do not agree.
     "But doesn't this tend to subvert the cause of faith?" one person asked me.  To this, I said that if a person is reasonably grounded in the fundamentals of her faith, and has (or has had) meaningful objective as well as subjective experiences and evidences of her faith, she can only benefit from such stretching.  Whenever we are living in a box, be it one of faith or unbelief, we cannot see what's outside of it.  We do not know what else there is to know.  Better that we be exposed to what is beyond or outside of what we believe than to live our lives ignorant of what our faith really means.  If all we have is our faith in a world that only our faith has created, that is really all we will ever have, that is, faith that has no genuine credibility or foundation or staying power.
     Besides, if indeed God is ultimate truth, he ought to be able to withstand any challenge raised against him.  To paraphrase Augustine's famous observation that, "I believe that I may understand," I suggest, "Believe, but explore; explore, but believe."  A real faith need not fear the world, for the world is in truth the work of God.
     So, I concluded, if my faith cannot successfully surmount questions about its veracity, then it is not a faith worth having and, if this is the case, real truth remains to be found.  And truth, after all, in its purest form, is the most important thing.