The year is 1738. A young Anglican priest in England is struggling with his faith. He has followed the religious system of his day. He has done all the right things. He has studied. He has even gone as a missionary to the wilds of America. But he can find no peace, no assurance of God's forgiveness in his service to God.
Under the influence of rationalism, as well as social and political pressures, the religious system of the 18th century Church of England offers only a bland Christianity that relies on ritual and outward observance. There is no life. The problem, you see, is that they are putting their trust, not in God, but in their idea of God. Religious system has become its own idol.
In his spiritual pilgrimage, John Wesley finally came to a realization that it is neither a religious system nor his efforts on which his salvation depends. It depends on God and God alone.
In the evening I went very unwillingly to a society in Aldersgate Street where one was reading Luther's preface to the Epistle to the Romans. About a quarter before nine, while he was describing the change which God works in the heart through faith in Christ I felt my heart strangely warmed. I felt I did trust in Christ, Christ alone for my salvation; and an assurance was given me that he had taken away my sins, even mine, and saved me from the law of sin and death.