Complex sentence: Antinomianism is the rejection of a socially established morality or the belief that under the gospel dispensation of grace, moral law is of no use or obligation because faith alone is necessary to salvation.
Split into simpler sentences: Antinomianism is the rejection of a socially established morality. It is the belief that, under the gospel dispensation of grace, moral law is of no use or obligation because faith alone is necessary to salvation.