Original: With the creation of the creed, a precedent was established for subsequent general (ecumenical) councils of Bishops (Synods) to create statements of belief and  canons of doctrinal orthodoxy— the intent being to define unity of beliefs for the whole of Christendom.
Simplified: With the creation of the creed, a precedent was established for subsequent 'general (ecumenical) councils of Bishops' (Synods) to create statements of belief and church law.