Now in order to correct these abuses, know first of all that a Christian congregation should never gather together without the preaching of God’s Word and prayer, no matter how briefly, as Psalm 102 says, “When the kings and the people assemble to serve the Lord, they shall declare the name and the praise of God.” And Paul in 1. Corinthians 14 [:26-31] says that when they come together, there should be prophesying, teaching, and admonition. Therefore, when God’s Word is not preached, one had better neither sing nor read, or even come together.(Luther’s Works, American Edition, Vol. 53. Liturgy and Hymns, p. 11.)
Luther wrote this because there were so many abuses, the worst among them the saying of masses without even anyone present to receive the supper, etc.
The most important always is the word, the hearing of the gospel and the praise of God. We cannot do without it. Just reading and reciting prayers is not sufficient either. When we gather there must be a word, a living word.