The religious belief that God cannot be known but is completely `other' and must be described in negative terms (in terms of what God is not) WordNet 3.0 & Open English WordNet

Apophatic theology, also known as negative theology, is a form of theological thinking and religious practice which attempts to approach God, the Divine, by negation, to speak only in terms of what may not be said about the perfect goodness that is God. Wikipedia

A way of describing the divine by explaining what God is not Wikipedia Disambiguation

Way of describing the divine by explaining what God is not Wikidata

A theory of approaching knowledge of God through negative rather than positive assertions. Wiktionary

A theory of approaching knowledge of God through negative assertions. Wiktionary (translation)