“A Christian church-community, whether a publicly visible congregation or a house-church, is held together by its assembling around the word… The concrete function of the empirical church, therefore, is worship that consists of preaching and celebrating the sacraments…Only when an individual outlook began to transform this obvious necessity into a psychological one did it ask about the meaning of the assembly in terms of its usefulness and necessity for the individual. This question reveals a fundamental misunderstanding of the concept of the church-community.
Since I belong to the church community, I come to the assembly; this is the simple rationale of those who are assembled. This act is not based on utilitarian considerations or a sense of duty, but is ‘organic’ and obvious behavior….It is here alone that the Spirit is at work and dispenses the charismata (gifts of grace). A Christian who stays away from the assembly is a contradiction in terms. The church-community, united by one word, hears this word again and again while assembled; conversely, the word that created the church-community again and again calls it together into concrete assembly.
Of course, this answer will not satisfy the individualistic inquirer. For cannot each member of the church-community read the Bible on their own, and in private profess that they belong to the church-community, namely the invisible church of the ‘conscience’ and the ‘soul’? What is the purpose of the deadly boredom of a publicly visible assembly in which one risks sitting in front of a narrow-minded preacher and next to lifeless faces?”
Dietrich Bonhoeffer, Sanctorum Communio 226-228