Who is God?

Who is God? Clearly no better answer occurs to me than, ‘He who is.’ He wished this to be answered of him; he taught this to Moses and urged him to say to the people, ‘He who is has sent me to you!Indeed, this is fitting; nothing is more appropriate for the eternity which God is.

If you should say of God anything: that he is good, or great, or blessed, or wise, or any such thing, it is summed up in this phrase which says, ‘He is’. For his being is what all these things are. If you should add a hundred such attributes, you would not go beyond his essence. If you should say these things you would add nothing; if you should not say them, you would take nothing away. If you have already perceived how singular, how supreme his being is, do you not judge that by comparison whatever God is not, is non-being rather than being?

Bernard of Clairvaux