The history of theology demonstrates that theological exploration, seeking to understand fully an already given theological concept, regularly brings forth unexpected insights. This article seeks to do just that. Reflecting on an ancient theological word, perichoresis, coined in its original Greek to express the intimate communion of, first, the two natures in the one person of Jesus and, second, the three persons in one God, the article seeks new theological insight into the communion that is essential in, first, Christian marriage and then, church. The analysis underscores communion-through-perichoresis as essential to the definitions of God, marriage, and church, and relates the three one to the other.