I'm not a christian, but I grew up in a Baptist household, so I have at least a passing understanding of the Bible. Lemme know if I got any wrong.
If I'm understanding the bible correctly;
God Created heaven and Earth, Including Mankind and Angels
God is all-knowing and all-powerful
Relevant to this discussion, God created Lucifer and all the angels who sided with him.
God made Man in His image, and ordered the angels to serve them.
Lucifer, prideful of his own beauty, and envious of God's (at least perceived) favoritism of Man, and of God's position, started a rebellion in heaven and was/will be cast down into the lake of fire(aka Hell).
lucifer later tempted/took the form of the Serpent in the Garden of Eden and tempted Eve to eat of the Tree of Knowledge.
my conclusion: God, with full knowledge of what lucifer would do/become created him and set him on the path that led to his downfall, and to the Sin of Mankind.
Or to put it more simply; God created Sin through his foreknowledge of what Lucifer would become.
I'm not trying to start a shitstorm here, but this is the logical conclusion that I find myself at.
Any Christian pedes wanna poke holes in this for me?
An all knowing God would know how the story of the devil ends. Maybe that was well worth all the millennia of suffering and struggle.