I stumbled on this video yesterday while looking for something else. But I'm always interested to listen to both Kennedy Hall and Fr. Ripperger.
Fr. Chad Ripperger, an exorcist, is always worth listening to. Here he explains how much the devil hates marriage and how he attacks the couple through their marital obligations. Much of this I'm sure couples haven't even considered. I certainly learned things that would have been useful during marriage preparation which was almost non-existent in 1969 when Larry and I married.
There are serious responsibilities in the contract of marriage. A covenant is, in fact, a sacred contract. Once the couple makes the commitment, each has serious responsibilities to the other. Kennedy points out the connection to the serious sin of contraception. The devil hates people. He'll prevent their conception if possible and, if they manage to be born, will do everything to keep them from every seeing the Kingdom of Heaven.
Watch the video. It's enlightening and sobering. Fr. Ripperger has a whole series on marriage that would be great for couples preparing for the sacrament. It starts here.