Robert Barclay (1648–1690), who wrote the first systematic exposition of Quaker theology, shows how knowledge comes from worship:

Not by strength of arguments or by a particular disquisition of each doctrine, and convincement of my understanding thereby, came [I] to receive and bear witness of the Truth, but by being secretly reached by [the] Life. For, when I came into the silent assemblies of God’s people, I felt a secret power among them, which touched my heart; and as I gave way unto it I found the evil weakening in me and the good raised up; and so I became thus knit and united unto them, hungering more and more after the increase of this power and life whereby I might feel myself perfectly redeemed; and indeed this is the surest way to become a Christian; to whom afterwards the knowledge and understanding of principles will not be wanting, but will grow up so much as is needful as the natural fruit of this good root, and such a knowledge will not be barren nor unfruitful.