Is Evil a Result of God's Omnicausality?
It can be proven through the Thomistic proofs of God's existence, that God is the Prime Cause of all that exists.
However, God created us with freedom of the will, to do good or evil, in the same way that a mother creates a child, who is free to do good or evil. If the child chooses to do evil, the mother is not the cause of the evil, the child is the cause of the evil.
Someone who wishes to do evil, does so without God's blessing, and therefore, that someone is the cause of evil - and not God.
Others will argue that God's omniscience - that God knows everything in the past, present and future - is proof that God knew evil was to happen and did not prevent it, and therefore, caused the evil by not preventing it when He could have.
That is just as erroneous as the previous argument for the same reason - we all have freedom of the will - and that freedom is given without reservation - else it is not freedom. As much as God "hates" evil, He cannot prevent it by taking away the freedom of the will He has given us. If God takes away our freedom of the will, we are nothing but robots - but we all know we can "choose" to obey God's simple laws or to ignore them.
To blame God for evil acts, therefore, is to blame the mother for the evil acts of one of her sons.
Use the freedom God gave you to spread goodness and you will reap rewards a hundredfold,
Carmen