Christian worship
A large amount of importance was placed on the forms of worship, as they were seen in terms of the Latin phrase lex orandi, lex credendi ("the rule of prayer is the rule of belief") — that is, the details of someone's worship show, teach, and govern the principle beliefs of the community.  To change the patterns and content of worship were to change the faith itself.  So even though there was always a certain amount of variety in the early Church's liturgical worship, there was also a great deal of unity.  Each time a heresy appeared in the Church, it normally came by a shift in worship for the heretical group. Orthodoxy in faith also meant orthodoxy in worship, and vice versa.