In 'Grace Abounding to the Chief of Sinners' Bunyan describes how the joy of other Christians helped him to see how much he needed God:
'But upon a day the good providence of God called me to Bedford to work at my calling, and in one of the streets of that town I came where there were three or four poor women sitting at a door in the sun talking about the things of God: and being now willing to hear their discourse, I drew near to hear what they said, for I was now a brisk talker of myself in the matters of religion; but I may say I heard, but understood not, for they were far above out of my reach. Their talk was about a new birth, the work of God in their hearts, as also how they were convinced of their miserable state by nature; they talked bow God had visited their souls with his love in the Lord Jesus, and with what words and promises they had been refreshed, comforted, and supported against the temptations of the devil; moreover, they reasoned of the suggestions and temptations of Satan in particular, and told to each other by what means they had been afflicted, and how they were borne up under his assaults. They also discoursed of their own wretchedness of heart and of their unbelief, and did contemn, slight, and abhor their own righteousness as filthy and insufficient to do them any good.
And methought they spoke as if joy did make them speak; they spoke with such pleasantness of scripture language, and with such appearance of grace in all they said, that they were to me as if they had found a new world-as if they were people that dwelt alone, and were not to be reckoned among their neighbors. At this I felt my own heart begin to shake and mistrust my condition to be naught, for I saw that in all my thoughts about religion and salvation the new birth did never enter my mind, neither knew I the comfort of the word and promise, nor the deceitfulness and treachery of my own wicked heart. As for secret thoughts, I took no notice of them, neither did I understand what Satan's temptations were, nor how they were to be withstood and resisted.'
Joy made these ladies speak! As they spoke Bunyan was challenged. He saw the pleasure of knowing God in these Christians. He saw their joy; their experience of Christ's beauty outwardly manifested. The happiness of these Christians were bright lights exposing Bunyan to the darkeness of his nature.