18 After taking all these factors into consideration, this Sacred Council solemnly repeats the declaration of previous Councils and Roman Pontiffs, that for the restoration or the maintenance of unity and communion it is necessary "to impose no burden beyond what is essential". It is the Council's urgent desire that, in the various organizations and living activities of the Church, every effort should be made toward the gradual realization of this unity, especially by prayer, and by fraternal dialogue on points of doctrine and the more pressing pastoral problems of our time. Similarly, the Council commends to the shepherds and faithful of the Catholic Church to develop closer relations with those who are no longer living in the East but are far from home, so that friendly collaboration with them may increase, in the spirit of love, to the exclusion of all feeling of rivalry or strife. If this cause is wholeheartedly promoted, the Council hopes that the barrier dividing the Eastern Church and Western Church will be removed, and that at last there may be but the one dwelling, firmly established on Christ Jesus, the cornerstone, who will make both one. II. Separated Churches and Ecclesial Communities in the West
Source: Unitatis Redintegratio (Vatican.va)