As the singing of human compositions in celebrating the praises of God, has its rise in small beginnings: no claim is at first offered on their behalf to the sole possession of this part of God’s worship. In the end, the psalms of scripture are excluded, and, perhaps, even reviled. Singing by choir begins very modestly: the object is merely to improve the music. In the end, the choir claims to be the seat of praise in the house of God. Trustees had no places in the apostolic church. There could have been none at that time. The reformed churches had no such officers. Originally, as there is reason to believe, they were barely tolerated, they are now, sometimes, supported as altogether preferable to deacons; and some, going still farther like the advocates of human psalmody, deny the office of deacon to be at all an important part of the order of the sanctuary. Trustees, man’s invention, they would not dispense with: deacons, Christ s appointment, may be very well neglected. The history of all the corruptions we have mentioned is the same, for the general principle will always hold good: a human invention, once tolerated in the church, will ultimately exclude, or throw into the shade, a divine institution.
James Willson, The Deacon, page 43, 1841
Exclusive Psalmody 