Your second link, if I understand correctly, claims that evil does not really exist, but it is simply the absence or limited presence of light.
But our Apostle Paul says there is >
"the spirit who now works in the sons of disobedience." (in Ephesians 2:2)
I understand this means an actual spiritual being who exists plus actually "works" in people. This word for work is translated from the same Greek word used to speak of how God Himself "works" in us > Philippians 2:13.
And Satan is one who is spoken as having "wrath", and "desires" > >
Revelation 12:12 > this says Satan has wrath, and the Greek word for wrath, here, is the same as the word meaning God's wrath.
Plus, John 8:44 shows Satan has desires; and, yes, the Greek word for desire, here, is the same in Luke 22:15 where Jesus says He has desire!
I think this supports that the spirit of evil and Satan is really in existence.
God Himself is a personal and feeling Being. But Satan in his way does exist and is personal and has feelings and desires, though not how love has someone feeling and desiring. In sin we have been very conscious but in misery and ruin and not really loving. We were not only in some sort of absence!
And Hebrews 2:14-15 says "fear of death" had us in slavery to Satan. And there is "spirit of fear" > 2 Timothy 1:7; also please see Romans 8:15. Fear is not only a feeling, but there is an actual existent "spirit of fear".
But if people find God to be mainly distant and theoretical, then I would say they can suppose sin and Satan and his evil spirit are only nonexistent, and absences. But if God has proven Himself in us, by changing us away from Satan and his kingdom, we know He got us out of real trouble > turning us "from the power of Satan to God", as Jesus says, in Acts 26:18.
There is power involved in evil. Worry works very hard, with power. And lusts are dominating and dictatorial with personal and conscious experience. But God is almighty; His peace has almighty power to keep our "hearts and minds through Christ Jesus", we have in Philippians 4:4-7.
So, succeeding against evil is not only an intellectual and philosophical thing.
So, it is vain to try to disprove God's existence, by claiming He would get rid of evil if He really exists. God is succeeding against evil, and with Him we have His safety almighty >
"You prepare a table before me in the presence of my enemies" (in Psalm 23:5).
"And who is he who will harm you if you become followers of what is good?" (1 Peter 3:13)
So, this is not merely a theoretical issue. We need how God proves Himself in us >
"There is no fear in love; but perfect love casts out fear, because fear involves torment. But he who fears has not been made perfect in love." (1 John 4:18)