From Prayer by Richard J. Foster:

Sometimes we are invaded to the depths by an overwhelming experience of the love of God. Walking down the streets of New York, D.L. Moody was so overcome by God's loving presence that he rushed to the home of a friend in order to have a room alone where, for two hours, wave after wave of God's ravishing love swept over him. At other times we experience such a flaming vision of light that we are forever blinded to all competing loyalties. In the center of his greatest spiritual moment Blaise Pascal wrote the single word "Fire!"