It's not easy being a "Christian band," especially when you don't fit in the easy-to-categorize box, which is the case for Relient K and mewithoutYou, playing the Marquee and Crescent Ballroom this week, respectively. From the beginning, both bands had no trouble attracting fans outside the youth group circuit, with Relient K's pop-punk sound appealing to fans of secular analogues in the early 2000s like Blink-182 and Sum 41, and mewithoutYou's angry post-hardcore working just as well as the soundtrack to a bad breakup as a prayer session. But both bands wasted no time complicating matters: The K moved into more dynamic melodic territory with records like Forget and Not Slow Down and MMHMM. And mewithoutYou ditched the GQ-approved suit-and-tie combos in favor of sweat-stained salvage garb and a swirling, psychedelic folk approach that mixed Eastern mysticism with ancient orthodox traditions long abandoned by mainstream Christianity (and that occasionally must have freaked out their former label, Tooth and Nail Records). Neither group abandoned its faith, but both took a longer route to it. Though Relient K has found favor with pop fans and Christian thinkers, mewithoutYou's spiritual excursions, like those found on their latest Daniel Smith-produced Ten Stories, have proved nearly as baffling to believers as they have to non-believers. Exactly how either fits into the broader spectrum of Christian rock is unclear, but both shows are guaranteed to be something other than the Bible-tossing Stryper extravaganzas of yore.