James Smith has a great answer:
This overreaching of the “all-of-life-is-worship” principle is part of a bad habit we picked up after the Reformation: the tendency to reduce worship to expression. After the Reformation, and especially in the wake of modernity, wide swaths of contemporary Christianity tend to think of worship only as an “upward” act of the people of God who gather to offer up their sacrifice of praise, expressing their gratitude and devotion to the Father, with the Son, in the power of the Holy Spirit.
Obviously this is an entirely biblical impulse and understanding: if we don’t praise, even the rocks will cry out. In a sense, we are made to praise. The biblical vision of history culminates in the book of Revelation with a worshiping throng enacting the exhortation of Psalm 150: “Praise the Lord!” But one can also see how such expressivist understandings of worship feed into (and off of) some of the worst aspects of modernity. Worship-as-expression is easily hijacked by the swirling eddy of individualism. In that case, even gathered worship is more like a collection of individual, private encounters with God in which worshipers express an “interior” devotion. It is precisely this model that prizes “authenticity” so highly.
The same expressivism is behind those versions of the “all-of-life-is-worship” principle that sees gathered Sunday worship as basically optional. It is a “Reformed” version of the “spiritual but not religious” canard that waxes eloquent about the “church” of nature and the sacred experience of a mountain sunrise.
But throughout the course of its history (including the Reformation), the church has always understood worship as more than expression. Christian worship is also a formative practice precisely because worship is also a “downward” encounter in which God is the primary actor. Worship isn’t just something we do; it does something to us. Worship is a space where we arenourished by Word and sacrament—we eat the Word and eat the bread that is the Word of life. This understanding of worship is equally central to the Reformation heritage, and it is at the heart of John Calvin’s legacy.
If we fail to appreciate that Word and sacrament are specially charged conduits of the Spirit’s formative power, it would be easy to imagine that worship can happen just anywhere. On the other hand, if we appreciate that Christian worship around Word and table is a unique “hot spot” of the Spirit’s wonder-working power, then we will also appreciate that the sanctuary can’t be replaced by just any other space in God’s good world, for it is in the sanctuary that we are made into a people of praise. In communal worship we receive the unique promise of the Spirit that is tethered to Word and sacrament.
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