antinomian (n.)

"one who maintains that, by the dispensation of grace, the moral law is not binding on Christians," 1640s, from Medieval Latin Antinomi, name given to a sect of this sort that arose in Germany in 1535, from Greek anti "opposite, against" (see anti-) + nomos "rule, law," from PIE root *nem- "assign, allot; take." As an adjective from 1640s.