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?
Sin is not something that needed to be created.
If there is existence, there is nonexistence. Similarly, if God exists, and is the purest good and truth there is in (and out of) the universe, then there must also be the state of not aligning with God.
That's essentially what sin is. The act of willful disobedience of God. That's why Lucifer was able to sin, as were Adam and Eve. They had free will to choose whether or not they wished to obey God.
It's like someone laying out a road in the countryside. Did that same person create any and all of the ways you can traverse the countryside off the road through the act of laying out the road? You could argue the case on a technicality, but I don't think reasonable people would say so. In the same way, considering the nature of God as the infinite good, veering away from God... you get the point.