Born in Waltersdorf, Heiligenbeil District, East Prussia (now Pęciszewo, Gmina Braniewo, Braniewo County, Warmian-Masurian Voivodeship), as the son of a pastor, Echternach attended school and university in Königsberg, graduating with the degree of the Licentiate in Theology.
One year later he founded an ecumenical discussion group within the Evangelische Akademie Hamburg for dialogue among Roman Catholic, Lutheran and Orthodox Christians.
Together with W. Michaelis, Echternach inaugurated the St. Ansgar vespers, a form of Lutheran high church liturgical celebrations, in 1965, which have become quite famous.
[1] On 18 October 1966 Echternach was consecrated to the holy order of episcopate by a bishop in apostolic succession.
He was called as professor of systematic theology at the Université Européenne in Amsterdam on 1 August 1970 and retired from active ministry in 1973.