When David Barclay was passing through that crisis in his spiritual history which resulted in his embracing Quakerism, he made no efforts to win his son to the same view. No doubt he had all a new convert's confidence in the power of "the truth." Probably he had also a Quaker's persuasion that though such efforts might sway the understanding, they could not "reach" the soul. He said he wished the change to come from conviction, not from imitation. The early Friends never considered themselves a sect, and did not seek proselytes so much as they sought to spread deep spiritual life. In the end at least, the laissez-faire method resulted in what the father wished. The son quietly looked around on the different classes of professed Christians. He felt his old repugnance to the Calvinists invincible. The latitudinarians, with all their professed charity and condemnation of "judging," pleased him no better. Finally, he gave his hearty allegiance to Friends within twelve months of his father's admission to their fellowship.
It is an interesting question, "What led such a clear and powerful mind to accept Quakerism?"
It could not fail to impress such a nature to see the great change which had passed over his father. The warrior and the man of the world had become a consistent Friend, trusting God to plead his cause, anxious most about spiritual wealth, careful most to walk closely and humbly with God. Further, it seemed to him that whilst others were wonderfully strict in creed, the Friends, whom they called heretics, far surpassed them in holy and exemplary living. Lastly, came the evidence that so often in those days turned the scale decisively in favor of the new brotherhood. The very first time that Robert Barclay attended a Friends' meeting he was struck by the awful Presence there; he felt that God was in that place. Some minister who was present used these epigrammatic words, which are said to have made a great impression on him. "In stilness there is fulness, in fulness there is nothingness, in nothingness there are all things." It is true that we are told that Sir John Swintoune and another Friend named Halliday were specially helpful to him at this critical time. But we have the clearest evidence that what most impressed him and attracted him to Friends was not their ministry, but the marvellous divine influence enjoyed in the period of silent waiting upon God. His intimate friend, Andrew Jaffray, bears testimony that he was "reached" in the time of silence. His own words, too, in his apology are unmistakable; they are introduced into his glowing description of an ideal Friends' meeting, as a personal testimony to the value of silent worship. Speaking of his own conversion, he says, "Who not by strength of argument, or by a particular disquisition of each doctrine, and convincement of my understanding thereby, came to receive and bear witness to the truth, but by being secretly reached by this Life. For when I came into the silent assemblies of God's people, I felt a secret power amongst 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 find myself perfectly redeemed." Apology, Prop. XI., Sect. 7.