This chapter considers the precise nature of God's knowledge and power. It provides that an intellectually respectable, logically coherent and theologically satisfying account of petitionary and intercessory prayer is possible in the light of certain strands of biblical teaching and of modern theological and philosophical understanding. The chapter talks about the subject of biblical prayer which seems to be descriptive and exegetical rather than enquire into the theological and philosophical basis of the matter. It argues that prayer is a means by which the supremely personal God enlists the freely-given cooperation of human persons in the realization of the divine purpose. As an instance of faith active in love, prayer both makes certain possibilities greater and strengthens the likelihood of divine response, so that those who pray may have every confidence that their prayers will make a difference to the world, through the God who both influences and is influenced by the creation.