Isaiah 45:7 says: 'I form the light, and create darkness: I make peace, and create evil: I the LORD do all these things.'
Yet Genesis 1:31 teaches that 'God saw every thing that he made, and, behold, it was very good.' I think God declared that everything he made was perfect. So how can He say that He created evil? I thought evil was not created, that it's not a creature, but the lack of God's goodness in the world.
Romans 5:12: 'Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned.' Who gets the blame for evil? If sin entered by man, then what does 'evil' refer to in Isaiah 45:7?
As you imply and say in your second post, everything God does is of maximum possible quality. He is perfect, all his ways are perfect, and everything he does is perfect, so there is never any reason for God to undo anything he finished. (But that's different than fixing something of his that we damaged or destroyed.)
God created Adam and Eve, then Adam and Eve (and God) created Cain, and Cain committed murder. Who shares moral fault for the murder? God teaches that it is just Cain (Ezekiel 18:20, 18:4).
If God has not prompted Satan in the book of Job, would Satan have been given the greater access to Job that God gave him? —which resulted in Satan murdering Job's family? Later Job queries, shall we not accept adversity as well as good from the Lord? Did God do evil by granting Satan this added access? Based on knowing God's nature, definitely not.
We lack enough details to understand why God behaved as he did at the beginning of Job. Perhaps a legion of demons was about to start a war against Job and kill all his brothers and sisters and also everyone in the whole region and burn the land. All Job's brothers and sisters that Satan killed were guilty of sin, and based on other Biblical narratives, it seems probable that they were actually swimming in sin. i.e., God didn't create conditions for murder, he allowed sin to have its way with them.
The starting point for knowing God in this life is to recognize that we all have earned and deserve eternal condemnation for our sin. (Since God does not hold us responsible for our parent's sins, the reason we are all born condemned is because we inherit our father's spiritual nature, which is not connected to God as was the case when God created Adam.)
If God chooses to just let us slide our way into hell, he has done nothing wrong. It is we who have chosen to do evil and have invoked the need for justice. The reality is that what is moral is that God punish all humans. All humans and the earth itself are tainted with sin.
Sin is everywhere and in everything. But God does not ignore us because we are tainted from sin. He deals with reality as it is. He loves us and is involved in the lives of people. It should not be surprising if we see him rearranging events so that the effects of sin are changed (Isaiah 43:4, Proverbs 13:22). In this sense God creates evil where there was none before
from our perspective. But no sin ever originated with God. Our sin has created an environment where it is not possible for pure good to have its way in
anything. It's not surprising that we see situations where God seems to have done evil. Thinking in terms of the cause-effect relationship, God is not the original
cause of any sin or evil, but he is the
effect, and sometimes takes responsibility for that as sovereign Lord of all who operates the (physical and spiritual) universe.