Complex sentence: The covenant marriage laws emphasize the belief that marriage is more than just a mere contract between two individuals, contending that without marriage, there would be no foundation of family in society and, in turn, no civilization or progress to follow.
Split into simpler sentences: The covenant marriage laws emphasize the fact that marriage is more than just a mere contract between two individuals. The argument contends that without marriage, there would be no foundation of family in society and, in turn, no civilization or progress to follow.