Negative theology, also known as the Via Negativa (Lat. for "Negative Way") and Apophatic theology, is a theology that attempts to describe God through negative attributes. In this theology, one should not say that God exists in the usual sense of the term; nor can we safely say is that God is not nonexistent. We can only say that God neither exists nor does not exist. The Cappadocian Fathers of the 4th century said that they believed in God, but they did not believe that God exists. God is beyond existing or not existing: these "relative" terms have no meaning where the absolute is concerned.

Some say that we should not say that God is wise, but we can say that God is not ignorant; others in the tradition insist that we can make no statements about the nature of God at all.

In the Christian tradition, it is generally accepted that we should not say that God is One, but we can state that there is no multiplicity in God's being. In brief, the attempt is to gain and express knowledge of God by describing what God is not, rather than by describing what God is.

Adherents of negative theology hold that God, by definition, is that which is utterly beyond this universe and outside the bounds of what humans can understand. Rather than producing straightforward, positive assertions about the nature of God, it speaks by way of negation.

God is described negatively as not a creation (uncreated), not definable in terms of space (infinite), invisible, beyond the reach of understanding (incomprehensible), whose being is not conceptually confinable to assumptions based on time. In other words, God's essence cannot be spoken of (ineffable), and can only be compared to what it is not (incomparable). In this view, it is not necessary or even possible to know the essence of God; knowledge of God is true knowledge, when it is limited to what is revealed, and does not presume to venture beyond this.

In contrast, making positive statements about the nature of God, which occurs in most other forms of Christian theology, is sometimes called 'cataphatic theology'.

Negative theology played an important role early in the history of Christianity. Three theologians who emphasized the importance of negative theology to an orthodox understanding of God, were Gregory the Theologian, John Chrysostom, and Basil the Great. John of Damascus employed it when he wrote that positive statements about God reveal ‘not the nature, but the things around the nature.' It continues to be prominent in Eastern Christianity (see Gregory Palamas), and is used to balance cataphatic theology. Apophatic statements are crucial to Orthodox Christian theology.

In contrast, some traditions in Christianity make prolific use of a concept called analogia entis (Analogy of being). By use of the analogy of being, known things and ideas are conceptually compared or projected toward a limiting concept which comprehends all possible, derivative or lesser versions of that ultimate idea. By finding relevant similarity and irrelevant dissimilarity, something of the being of God can be known. Apophatic theology is critical of this approach, presupposing that it is doomed to result in false, idolatrous conclusions, when applied to the discovery of the being of God.

Negative theology is crucial to understanding many parts of Jewish philosophy, especially the philosophy of medieval Jewish rationalists such as Maimonides and Joseph Ibn Tibbon.

Negative theology is present in the Upanishads of Hinduism, when Hindu Vedantic theologians speak of the nature of Brahman. Many East Asian traditions present something very similar to the apophatic approach: for example, the Tao Te Ching, the source book of the Chinese Taoist tradition, asserts in its first statement: the Tao ("way" or "truth") that can be described is not the Tao.