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 . A great deal of emphasis 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 specifics of one 's worship express , teach , and govern the doctrinal beliefs of the community .