Ari Ezra Waldman believes people of faith are essential to winning the marriage equality battle:

To persons of faith, DOMA's definition of valid marriages for the purposes of federal law discriminates against those faiths that would define marriage differently. Whereas Gill's attorneys and the Department of Justice argued that DOMA fails a constitutional test because it treads on powers traditionally and exclusively left to the states and because it treats similarly situated individuals simply because of their sexual orientation, the amicus brief from our religious allies argued that DOMA departed from the federal government's traditional neutrality among various religious definitions of marriage, enshrining one — a particularly conservative and arguably ahistorical Judeo-Christian definition — as the only federal definition of civil marriage. In this way, DOMA violates the Constitution's ban on the establishment of religion, or the favoring of one religious doctrine over another.