Abstract: This book is about what it is for there to be a God, and what reason there is to suppose that God to be the traditional Christian God. Part 1 (Chs.1 to 5) analyses the metaphysical categories needed for this purpose – substance, cause, time, and necessity. Part 2 (Ch. 6 to 10) begins by setting out some of the different ways in which the doctrine that there is a divine individual (an individual with the traditional divine properties) can be developed. There can be more than one divine individual so long as a first such individual is necessarily the cause of the existence of the others. Given the supreme moral goodness of cooperating with one individual in sharing everything with a third individual, it follows that if there is one divine individual, there will be three and only three such individuals; hence the necessity of the Christian doctrine of the Trinity – that there is one God consisting of three divine persons. One of these persons may choose to become incarnate, i.e. human, and there are reasons why he would do so.

Keywords: cause, God, Holy Trinity, incarnation, metaphysics, necessity, perfect goodness, philosophy of religion, substance, Richard Swinburne, theology, time, Trinity