Quakerism …. is a Christianity which emphasizes the importance of intense inner conviction and a hostility to outward and visible ceremonies and forms, although historically in its plain dress and peculiar speech it did precisely what it criticised others for doing. One of the effects of this suspicion of outward things is the Quaker view of the atonement which gives rise to certain tensions that I don’t think have ever been satisfactorily resolved.
Consider the First Advice of London Yearly Meeting, adopted in this form in 1931:
Take heed dear Friends to the promptings of love and truth in your hearts, which are the leadings of God. Resist not his strivings within you. It is his light that … leads to true repentance. The love of God draws us to him, a redemptive love shown forth by Jesus Christ in his life and on the cross. He is the Way, the Truth and the Life. As his disciples, we are called to live in the life and power of the Holy Spirit.
Friends have always set themselves strongly against what they consider to be a pusillanimous Christianity which says that Christ’s death frees you from the consequences of sin but leaves you in a continuing sinful state. They have always been deeply aware of access to an inward, mystical, spiritual power which they call the Light of Christ Within and which they identify both with God and with the carpenter of Nazareth. It is a source of wisdom and understanding, and has a power of total transformation. In a word, it saves, and Quakerism has always claimed that there can be no true Christianity without an experience of this power. The Light shows you your sin, and gives you power to overcome it.
–John Punshon in Pendle Hill Pamphlet 245: Alternative Christianity