“Our churches teach that one holy Church is to remain forever. The Church is the congregation of saints in which the Gospel is purely taught and the Sacraments are correctly administered.” (AC VIII) For the true unity of the Church it is enough to agree about the doctrine of the Gospel and the administration of the Sacraments. It is not necessary that human traditions, that is, rites or ceremonies instituted by men, should be the same everywhere. As Paul says, “One Lord, one faith, one baptism, one God and Father of all.” (Concordia: The Lutheran Confessions-A Reader’s Edition of the Book of Concord, ed. by Paul T. McCain, et al. (Saint Louis: CPH, 2005), 60.
The presence of the church is not dependent upon our faith and profession, but upon the real presence of Jesus Christ: ubi Christus, ibi ecclesia. But Christ is present in the Word of His Gospel even when our human understanding of this Word is partial or false; and He is present in His Sacrament even when we have an imperfect or wrong conception of the Sacrament. – Hermann Sasse, Here We Stand, 182.
Most attempts to define the church, or rather, to describe the church, conceive of the church as a societas, a visible community of people … But this path has never led to an understanding of the church. For the church is indeed a societas, but it is still something else. No treatment of the church which begins with people, with human communities, with the faith of people, ever leads to that other aspect of the church which the NT describes with the words “body of Christ.” – Hermann Sasse, “Church and Churches,” 81.
The presence of the Holy Spirit in the ekklesia is therefore not to be thought of without the real presence of the Crucified and Exalted One. In the light of this presence of the Lord and the Spirit, the church is to be understood: Ubi Christus, ibi ecclesia; ubi Spiritus Sanctus, ibi ecclesia. If one asks about the church, one may not first put the question “Where are the people who belong to the church?” but one must ask, “Where is Christ, where is the Holy Ghost?” And the answer to this can only be this: Christ is really present in the word of the Gospel and in the Sacrament; the Holy Spirit is really given through the Word and the Sacrament. Where the Gospel and the Sacraments are, there people are called into the church, there comes into being the congregation of the saints, that is, of the justified sinners—a community not to be understood by means of sociology. – Hermann Sasse, “The Church as Corpus Christi,” 117-18.