20 Our thoughts turn first to those Christians who make open confession of Jesus Christ as God and Lord and as the sole Mediator between God and men, to the glory of the one God, Father, Son and Holy Spirit. We are aware indeed that there exist considerable divergences from the doctrine of the Catholic Church concerning Christ Himself, the Word of God made flesh, the work of redemption, and consequently, concerning the mystery and ministry of the Church, and the role of Mary in the plan of salvation. But we rejoice to see that our separated brethren look to Christ as the source and center of Church unity. Their longing for union with Christ inspires them to seek an ever closer unity, and also to bear witness to their faith among the peoples of the earth.
Source: Unitatis Redintegratio (Vatican.va)