How can an all-good God make evil? Christians say he cannot. They say that evil does not really exist—it is just good in the wrong place or a lack of good. Christians say that if evil is a real thing and a power, and God makes it, then God is at least partly evil.
2+2=5 is a real sum despite being the absence of correctness—it is real despite giving wrong information. The 2 is a real number. The plus tells us things can be added together. The equal to tells us that a conclusion should follow. The 5 is a real number. A lot of right information is in the same despite the wrong result.
It is as real a statement as, "This statement is false. Is it true or false?"
Reality exists even when correctness is absent. Error does not imply non-existence; it implies deviation from the ideal.
2+2=4 is the absence of non-correctness as well as the presence of correctness.
Some will say that 2+2=5 is meaningless, for 2 and 2 cannot be 5. So it is only an equation on paper, but is really just nothing at all. But if we were programmed to perceive 2+2=5, like a computer might be, then the equation would be real in the only way that matters to us. Despite 2+2=4 in reality, 2+2=5 is true for us. We say that 2+2=4 is a real equation for us, for we perceive it to be right, so 2+2=5 can be like that too and be as real to us. Correctness is another word for good.
We have learned that logically a bad calculation is good in the wrong way.
We have learned that psychologically a bad calculation can be true and good for us.
Evil is getting your sums wrong; e.g., it is working out that good + evil = good.
That can happen either or both ways as with the sums.
If evildoing or sin is failing to make good as good as it can be then it follows that you don’t have free will, when defined as making true choice between evil and good.
You would not be committing any wrongdoing unless there were something wrong with you. The will is meant to be good, but it falls short, which makes wrongdoing or sin an accident that appears to be our own fault but is still an accident.
When God is supposed to be perfect, he cannot sin on this definition of evil, for he cannot fall short. We should have been made that way too. He is evil, for we are not. He didn't make us healthy but made us unrighteous—or so he says.
The notion that evil is a negative means that murder is not real, but is just making life absent. That is very inadequate, and you can imagine a narcissist or psychopath agreeing with that. Hitler thought that way about the Jews. Now religion wants us to think that God is different from us and thinks that way! Nature tells us to affirm: "To say that evil is not real is to deny the obvious. It is real. Those who refuse to admit that are themselves evil!"
To turn evil into a mere subtraction is a new level!
NOTE: Evil being seen as privation risks us logically and/or psychologically becoming too accepting of it. There is more. Theism says that though evil is a privation always, that when we commit it, we take good and abuse it. This amounts to putting good in the wrong place and time, the wrong direction. This teaching is considered to downplay the harm our actions do - it implies that looking at the good and how to do it better is all that matters.