Newly engaged couple Sadie (Mandy Moore) and Ben (John Krasinski) look forward to a traditional wedding in St. Augustine's Church but, unfortunately for the lovebirds, the Rev. Frank (Robin Williams) refuses to bless the union until they pass his arduous marriage-prep course. While the clergyman puts the couple through holy hell, Ben and Sadie learn if they are truly destined to love each other till death do them part.