St. Sophrony (Sakharov): God is humility

Generation and generation of those who have prayed before us - and, indeed, the Holy Scriptures also - have addressed God after His theophany, in respect of His relations to us, His manifestations: God is Light, God is Truth, Love, Mercy, and much else. I would make bold to add: God is humility. Nothing which is unclean - which means proud - can draw near Him. Pride is abomination, the opposite of Divine goodness. Pride is the principle of evil, the root of all tragedy, the sower of enmity, the destroyer of peace, the adversary of divinely-established order. In pride lies the essence of hell.
Pride is the 'outer darkness' where man loses contact with the God of love. "Men loved darkness" (John 3:19). Repentance alone can deliver us from this hell.
+St. Sophrony (Sakharov) from We Shall See Him as He Is, chapter 3, Concerning Repentance.