Paul asked God for encouragement to strengthen believers of Corinth to live in harmony with each other. That would make them able to glorify God with one voice, to follow Christ, to be in harmony, and to have patience and endurance. 

To have a harmonious Christmas, we must have an attitudinal change. Our minds must be in right relationship with Jesus, and not be lukewarm. For a harmonious Christmas, we’ve got to be in balance. We must be coherent. Harmony is to understand that there is no Christmas without Jesus: The Father, Son, and Holy Ghost.