Sorry, FK, wrong. Evil is quite real, very tangible and substantial. You recite, I am sure, the Lord's Prayer. In English, the final words are "...but deliver us from evil." The original Greek says, "alla rusai hmas apo tou ponhrou", "...but deliver us from the evil ONE."
Evil, my brother, is not merely the absence of something, even the "absence" of God (which is of course an impossibility)
Hm. Convince me.
Here's the problem. God did not create evil. There is no other creator. Evil therefore is absence of God, rather than a created substance. Evangelist John explains the paradox by describing God as light and evil as darkness, -- absence of light -- in the first chapter of his gospel.
We can, of course, say that Satan, who was created an angel, remains tangible and substantial even following his fall from grace. This is the usage in the Creed (*). But we cannot blanketly reject the formulation that evil is an absence rather than a presence.
(*) The Russian translation of the Creed dispenses with "evil" altogether and pleas to "deliver us from the deceiver".