What is the initial burden of persuasion under RLUIPA?

Under RLUIPA, plaintiffs bear the initial burden of persuasion on whether the Policy "substantially burdens" their "exercise of religion." 2000cc-2(b). RLUIPA defines "religious exercise" to include "any exercise of religion, whether or not compelled by, or central to, a system of religious belief." 2000cc-5(7)(A). A "substantial burden" occurs "where the state ... denies [an important benefit] because of conduct mandated by religious belief, thereby putting substantial pressure on an adherent to modify his behavior and to violate his beliefs." Warsoldier v. Woodford, 418 F.3d 989, 995 (9th Cir.2005) (alteration in original) (quotation omitted).