67 Doctrinal and historical disagreements at the time of the Reformation emerged with regard to the Church, the sacraments and the ordained ministry. The Council therefore calls for "dialogue to be undertaken concerning the true meaning of the Lord's Supper, the other sacraments and the Church's worship and ministry". The Decree Unitatis Redintegratio , pointing out that the post-Reformation Communities lack that "fullness of unity with us which should flow from Baptism", observes that "especially because of the lack of the Sacrament of Orders they have not preserved the genuine and total reality of the Eucharistic mystery", even though "when they commemorate the Lord's Death and Resurrection in the Holy Supper, they profess that it signifies life in communion with Christ and they await his coming in glory".
Source: Ut Unum Sint (Vatican.va)