Perhaps the primary idea of the church was fellowship. It was the corporate and social outcome of individual relation to Christ. Christianity is social as well as personal. The very nature of Christ’s salvation was to create a community. Paganism might show the beauty of the old humanity, but Christianity created a new. The church is a society of sinners saved by Christ.
But fellowship will necessarily express itself in service. The possession of Christ will lead to witness and work, for the church will inevitably endeavor to extend itself while, at the same time, it builds up its own members. At this point is seen the importance of the church to the individual. It is not without point that the creed first expresses belief in the “holy catholic church,” and then follows immediately with a phrase in explanation and amplification of it, “the communion of saints.” Individualistic Christianity is a contradiction in terms. While a man is justified solitarily and alone, he is sanctified in communion with others. Christian character needs the community for development, for it is only possible in fellowship with members of the Christian church (Ephesians 3.18; 6.18). There is no future for any Christianity that does not express itself through a community. Mysticism, by itself, is too vague and individualistic. While Christianity is mystical, it is much more. Mere individualism is equally impossible, for “unattached” Christians find no place in the Christianity of the New Testament. It is a great mistake to associate individualism with what is sometimes regarded as “ultra” spirituality, which is often opposed to organized Christianity.
From: The Principles of Theology: An Introduction to the Thirty-Nine Articles by W. H. Griffith Thomas (London: Longmans, Green, and Co., 1930), pp. 267-268.