Christianity is not just a set of moral commands. It is not just belonging to a church. It is not just remembering its founder of long ago! It is all of these, but far more, it is a vital relationship with a living and loving God!
And it is the Holy Spirit, third Person of the God-head, who makes this happen. "Vinculum amoris" is Latin for "bond of love", which describes the essential activity of the Spirit.
Because the Spirit links us to God, he saves us, guides and empowers us. He enlivens our worship, such as in baptism and the Lord's Supper. He stimulates our praying, and gives gifts to deepen the quality of our lives and service to God. Because he links us to God, we are linked to each other in a deeper way.
Enriching? yes! And the more that we understand how the Spirit does it, the deeper this enriching will be. The author's prayer is that this book will do just that for God's people and for his Church.