Excellent post by the folks over at Desiring God:
Jonathan Edwards says that a lack of external expression in worship can actually destroy Christian community and devotion.
Some bodily worship is necessary to give liberty to our own devotion; yea though in secret, so more when with others . . . ‘Tis necessary that there should be something bodily and visible in the worship of a congregation; otherwise, there can be no communion at all. (From Miscellanies #101)