41 What has been said above about ecumenical dialogue since the end of the Council inspires us to give thanks to the Spirit of Truth promised by Christ the Lord to the Apostles and the Church (cf. Jn 14:26). It is the first time in history that efforts on behalf of Christian unity have taken on such great proportions and have become so extensive. This is truly an immense gift of God, one which deserves all our gratitude. From the fullness of Christ we receive "grace upon grace" ( Jn 1:16). An appreciation of how much God has already given is the condition which disposes us to receive those gifts still indispensable for bringing to completion the ecumenical work of unity. An overall view of the last thirty years enables us better to appreciate many of the fruits of this common conversion to the Gospel which the Spirit of God has brought about by means of the ecumenical movement.
Source: Ut Unum Sint (Vatican.va)