In his exposition of the Decalogue, Calvin asks why the ten commandments are divided into two tables, the first table setting forth our duty toward God and the second table setting forth our duty toward man. He answers:
"The first foundation of righteousness undoubtedly is the worship of God. When it is subverted, all the other parts of righteousness, like a building rent asunder, and in ruins, are racked and scattered. What kind of righteousness do you call it, not to commit theft and rapine, if you, in the meantime, with impious sacrilege, rob God of his glory? or not to defile your body with fornication, if you profane his holy name with blasphemy? or not to take away the life of man, if you strive to cut off and destroy the remembrance of God? It is vain, therefore, to talk of righteousness apart from religion. Such righteousness has no more beauty than the trunk of a body deprived of its head. Nor is religion the principal part merely: it is the very soul by which the whole lives and breathes. Without the fear of God, men do not even observe justice and charity among themselves. We say, then, that the worship of God is the beginning and foundation of righteousness; and that wherever it is wanting, any degree of equity, or continence, or temperance, existing among men themselves, is empty and frivolous in the sight of God" (Calvin, Institutes, 2.8.11; Beveridge).
I like this quote because it suggests that how the church honors God in corporate worship, how the church teaches its members to revere, honor, and glorify God, has implications for the way we live the Christian life. Religion (in the sense Calvin means it, i.e., the fear of God) is the foundation of ethics. Get the vertical right, and the horizontal will follow. Get worship right, and mission will follow. This is contrary to those who imagine that the church can pursue the horizontal plane of being missional and reaching out to the culture, without first being rooted in the vertical aspect of worship. Worship is not a missional, horizontal, cultural, or evangelistic activity. In worship the redeemed covenant community gathers into the holy presence of God to be wholly occupied with God in union and communion with the Father through the Son by the Spirit. Love for neighbor flows from love for God. To subordinate worship as a means to the end of mission, is to lose the very motive of mission, for mission is a means to the end of worship. A church that structures all of its activity toward the horizontal plane becomes a body without a soul, a trunk deprived of its head. Only a church that is focused on the worship of the living, triune God will have the inner vitality needed to be a credible witness to the world.