This thesis investigates the development and significance of the idea of the human being as made in the 'image of God', from its origin in the book of Genesis through its historical and philosophical unfolding. There are, however, many interpretations of what this means, giving rise to problems regarding what precisely is being conveyed by this idea, The issue of the existence of God became particularly problematic after Hume and Feuerbach's scepticism and, in more recent times, in light of criticisms stemming from Darwin's theory of evolution and by some neo-Darwinists who claim to prove in particular that God does not exist. This study argues that the natural-scientific theory of evolution does not, in fact, prove the non-existence of God. It also argues that the phenomenological method of enquiry is a more appropriate method for addressing the question of what it is to be a human individual made in the 'image of God'. Because the idea of the 'image of God' rests on an assent to belief in God's existence for it to have meaning, in conclusion an argument for this assent is presented in light of Edith Stein's phenomenology. Yet, even if existence in God is not assented to, the idea of the 'image of God'can still be thought valuable in that this idea can be held to have been a precursor in the history of thinking for ideas such as human dignity and human rights.