Kommission für Glauben und Kirchenverfassung
Hopko was an Orthodox Christian lecturer and speaker, known both in Orthodox and ecumenical circles. He served as a member of the Faith and Order Commission of the World Council of Churches and as a delegate from the Orthodox Church in America to the Assemblies of WCC in Uppsala, Sweden and Nairobi, Kenya. He was also President of the Orthodox Theological Society in America (1992–95). In retirement, he had several popular podcasts on Ancient Faith Radio.