"The second is this: 'You shall love your neighbor as yourself.' There is no other commandment greater than these."
Mark 12:31
See: Notes on Mark by Thomas L. Constable
Publisher: Constable's Bible Study Notes
See Sermon: The Apostles' Creed (Part 10) - The Holy Catholic Church, the Communion of Saints by Matt Chandler
Publisher: The Village Church
Info from GetContent.xyz