i do not discount your point, dot. i don't even really disagree with it, particular as worded in this comment above.
i definitely agree that "anarchist" is most useful as a descriptor (adjective), rather than an identity (noun/label). not your words, i know, but i think the idea is the same, or at least very similar. so perhaps my answer is not directly addressing the question, as it is worded.
and like i said, i think it is possible they could act - or even think - in anarchist ways. but a desire for an overall life of anarchy (as i desire it)? hard to imagine.
"if christians challenge the church, challenge the state, challenge each other and themselves... "
if they are not challenging their belief/faith, then... again, hard to imagine.
but i guess a key point is this: intent cannot be ignored. anyone can act in ways that are (or appear to be) anarchistic. from capitalists to fascists to religionists of all stripes, folks do in fact behave, in some situations, in anarchistic ways. but where does that behavior come from, and what are they really trying to accomplish? in the case of a religious person, i suspect they would often be doing so out of moralism, or charity, or some other laws/rules that come out of their faith. just as with a capitalist, i would be highly suspicious of their motives.
the fact is i may have real affinity with their anarchistic behavior, and even to some extent with the person themselves. but ultimately, my affinity with them as an individual would be influenced hugely by what i see as their overall objectives and motivations. and i find it quite difficult to envision a truly religious individual truly desiring the kind of anarchistic world that i desire.
bottom line: i don't really give a shit who calls themselves anarchist. i will choose to associate with those i find it most enjoyable to associate with. that is unlikely to be anyone that identifies with christianity (or any other religious dogma). but that doesn't mean i won't appreciate what some religionist does in some situations; or even, in some cases, choose to associate with them in some meaningful way. i try my best not to be dogmatic. but no doubt i sometimes fail at that.