(Psalms 18:11) He made darkness his secret place; his pavilion round about him were dark waters and thick clouds of the skies.
Note God is not the God of darkness, so to further understand the text is to know this:
The darkness spoken of here does not imply the darkness of man, wherewith the evilness of man abides, less they be exposed. Rather the darkness here does represent the secret of God as to those who do not know Him through fellowship, thus the phrase after "darkness", is His secret place. Unto us who are safe, the once secret of the Lord, is now the revelation of our God. But for those who are without salvation nor fellowship with the Lord, His presence is but a dark cloud of mystery.
Men seek the dwelling of darkness as his secret place for the attribute of being morally wrong in principle or practice. But the darkness spoken of here in this verse is the mystery and dreadfulness that does befall the mind that is at enmity with God. But out of the thick dark clouds process the power of lightning. The result of which illuminates its surroundings or destroy that which it comes in contact with. Therefore, do you see the mystery of God as darkness which shall bring forth the power of light to illuminate? Or is the mystery of God a dark cloud from which shall come forth the burst of lightning to destroy you due to your enmity toward God?