Modern anti-ecumenism in Orthodoxy is grounded in a sacramental or eucharistic ecclesiology which identifies Christianity and the church exclusively with the Orthodox Church and stands in opposition to universal baptismal ecclesiology. This neo-traditionalist ecclesiology stresses the unity of the sacraments of baptism, chrismation and eucharist as equally necessary for membership in the church, identified exclusively with the Orthodox Church. It exploits a weakness in Orthodox eucharistic ecclesiology, according to which the church, identified with the Orthodox eucharistic community, can be interpreted as excluding non-Orthodox Christians from the church. The article demonstrates that this anti-ecumenical, exclusivist ecclesiology is contrary to several major aspects of the Orthodox tradition.