Some people believe that the Lord created evil. This is absolutely wrong as will be proven below.
Assume for a moment that the Lord did create evil.
What is the positive aspect of this belief? How does it help one to admire and love the Lord?
(In my opinion it besmirches Him and makes Him into a cruel manipulator).
Calvinism is simply wrong for this very reason. It proceeds from the point that the serpent made to Eve -
"The Lord is evil. He is holding out on you. He is threatening you. He is trying to control you. He is lying to you. You can't trust Him. Go your own way." - Satan
A question:
When loving parents raise their child to follow the Lord and the child grows up into a cruel, selfish, debauched individual, is that the parent's fault? Did they create the evil in him?
No. He chose. It is as simple as that.
The Lord gave us the right to choose. Was that evil of Him or an aspect of His love?
Our answer to this question will either enhance our faith in the Lord or eventually destroy it.
The Law teaches us to fear the Lord.
Grace teaches us to love the Lord.
The evil attributed to the Lord by implication in the OT was nullified by the Truth, Jesus Christ, whose life, death and resurrection proved that the He is amazingly good - that He is love - that there is no shadow of turning in Him.
Jesus commanded us to have faith in Him
That is impossible without being fully persuaded that the Lord is perfect love - that He is good - that He is altogether lovely.
Eating of the tree of the knowledge of Good And Evil brought about spiritual death in Adam (and so to all humanity). The spirit is supposed to rule the soul which, in turn, rules the body.
Once the spirit of man was dead the struggle between the soul and body was on. In the end, the body won out - our five senses - so that the unregenerated man is enslaved to the lust of the flesh. They cannot help themselves.
This is why Jesus said we must be born of the Spirit so that the order (of spirit over soul over body) that the Lord ordained is reestablished in us.
Once we have been born of the Spirit we have power over sin to command the mind and emotions and so to rule our bodies. In a believer's life, separation from sin is an act of our will inspired by the Spirit.
The poor sinner who has not the Spirit of the Lord is at the mercy of their flesh which ultimately will destroy them.