Here is a description of early Christian worship from Justin Martyr, writing about the middle of the second century A. D. :
And on the day called Sunday, all who live in cities of in the country gather together in one place, and the memoirs of the apostles or the writings of the prophets are read, as long as time permits; then, when the reader has ceased, the president verbally instructs, and exhorts to the imitation of good things. Then we all rise together and pray, and, as before said, when our prayers is ended, bread and wine and water are brought, and the president in like manner offers prayers and thanksgiving, according to his ability, and the people assent, saying Amen (as quoted in John Stott, Between Two Worlds [Eerdmans, 1982]: p. 19).
It is striking to note how that has time has passed the same primal elements still constitute the basics of Christian worship on the Lord’s Day. We gather together in one place, read the Scriptures, listen to the word preached, pray, and break bread. Corporate worship is our primary act of service as God’s people.