Although I disagree with a few strands of his overall theology, I appreciate what Ethelbert Stauffer writes about corporate Christian worship in his New Testament Theology [(Macmillan: 1955), 201]:

The worship of the primitive Church at every point took it back to the coming of Christ, the Christ-event. So it is the good news of the gospel that constitutes the real centre of her services of worship. The Word of Jesus Christ must have its course, said Luther, in the German Mass. It must dwell amongst us richly, declared Paul (Col. 3.16; cf. 1.27). So it came about that the prophecies and histories of the OT were read and expounded; the sermon set forth the mighty acts of God in the fulness of time (Acts 13.15 ff.); the correspondence of the apostles, new and old alike, the epistles, which are very much like sermons when read to the congregations, these were read and so, with their message, their thanksgivings and doxologies, helped to bring out the full meaning of Christian worship.

But Christian worship was ‘also’, most certainly, a service to the world. Yet the primitive Church did not serve mankind in solemn rites and cultic practices, in pious instructions and edifying spirituality. Christian worship rooted men out of their self-centred individualism into an extra nos — away from all that is subjective — up to that which is simply objective. This was its service to humanity. It summoned the nations to worship the crucified.