The heart is like a castle that is in danger every hour to be assaulted; this makes a child of God to be always a sentinel, and keep a guard about his heart.
Music and liturgy can assist or express a worshipping heart, but they cannot make a non-worshipping heart into a worshipping one. The danger is that they can give a non-worshipping heart the sense of having worshiped. So the crucial factor in worship in the church is not the form of worship, but the state of the hearts of the saints. If our corporate worship isn’t the expression of our individual worshipping lives, it is unacceptable.