The Supreme Court generally conditions tax - exemptions, deductions, and- exclusions for religious organizations and activities upon the simultaneous extension of such benefits to secular institutions and undertakings. The Court's position flows logically from its acceptance of the premise that tax exemptions, deductions, and exclusions constitute subsidies. However, the "subsidy" label is usually deployed in a conclusory and unconvincing fashion. The First Amendment is best understood 'as permitting governments to refrain from taxation to accommodate the autonomy of religious actors and activities; hence, tax benefits extended solely to religious institutions should pass constitutional Muster as recognition of that autonomy.
Edward A. Zelinsky, Are Tax "Benefits" for Religious Institutions Constitutionally Dependent on Benefits for Secular Entities?, 42 B.C.L. Rev. 805 (2001), http://lawdigitalcommons.bc.edu/bclr/vol42/iss4/3