If God created everything, doesn't that mean He also created evil? This argument is older than atheism. But a careful reading of the Bible, along with an adequate understanding of philosophy, will reveal that evil is not a creation of God, neither is it really even a thing.
Think of a donut. Though there are many types of donuts, when you hear "donut", you probably think of the type that has a hole in its centre. Now, does the hole exist? Actually, no. The holes existence is due to the fact that the donut doesn't exist in that space. A host can exist without a hole, but a hole cannot exist without a host. Evil is like a hole. Good can exist without evil, but evil cannot exist without good. Its existence is dependent entirely upon the fact that it is not good.
In the creation account found in Genesis, we see that God actually created a very good world, and then He stopped creating. When God's creative acts ceased, there was no evil. So where did evil come from? Us.
When God created man, He gave them only three commands: Fill the earth, subdue the earth, and you can eat from any plant except the tree of knowledge. These three commands were good. However, man chose to eat from the tree, which was evil. On man's part.
We often get confused about the tree. Why did God put it there if it was so evil? The truth is, the tree itself is not important. What matters is that Adam did what God told him not to do. It was good for Adam to obey, it was bad for him to disobey. God cannot be blamed because Adam disobeyed, for the same reason the government cannot be blamed for the existence of criminals. The law itself is not evil. In fact, when you remove the law, you have anarchy. Total chaos. The removal of the law would decrease the crime rate to zero. But this would be a ridiculous solution to crime. The law itself is good, but you can choose to break it. When you choose to break it, you chose to break it. In the same way, when you choose to do evil, you chose to do evil.
Two attributes of God are often invoked to rescue the problem of evil here: His omnipotence and omniscience. It is said that because God knew Adam would sin, yet created him anyway, He is still responsible for his sin, and that because God is all powerful, He should be able to stop Adam from doing evil anyway.
This reasoning is fallacious. When a husband and wife have a child, they know that pain and misery will result. The wife struggles carrying it for 9 months, then there is the pain of childbirth, and then eventually, the child is guaranteed to die. Is the parent responsible for the death of the child, which is the only thing they 100% know is going to happen? Of course not! The parents responsibility ends at creating life, which is a good thing, not at creating death, which is an evil that could not happen if the life was not created. Similarly, just because God knows evil will result from creating good does not make Him responsible for the evil.
But shouldn't He have the power to stop it? This comes from a fundamental misunderstanding of God's omnipotence. Omnipotence is not the ability to create a true contradiction. There are several things the Bible says God cannot do, sometimes as a necessary conclusion (e.g. if God cannot be tempted to sin (James 1:13), God cannot sin), sometimes as an explicit statement (e.g. Titus 1:2, "God, who cannot lie"). And so if the Bible itself says there are things God cannot do, omnipotence cannot mean the ability to create a true contradiction. Therefore, this attempt to rescue the problem of evil is a straw man argument. God could not have stopped Adam from sinning without removing his free will.
But let's grant it. Let's pretend there is nothing wrong with the atheist definition of omnipotence and allow God to contradict Himself. Your issue now is that God can contradict Himself. So where do we go from here? Well, God can be omniscient, omnipotent and omnibenevolent, and yet still take no responsibility for the existence of evil, even if He created a bunch of evil men and specifically commanded them "thou shalt be evil" and released them into this world, complete with weapons, superpowers, and an insatiable appetite for debauchery.
So, if you take God's omnipotence in context, the problem of evil doesn't work. If you don't take God's omnipotence in context, the problem of evil doesn't work. In both scenarios, the problem of evil is obsolete, as it tries to make God, who created a "very good" world, responsible for evil, which we brought into it and continue to stain it with today. It's like trying to blame a car manufacturer because a bank robber used their car to get away.
But the truth is, evil still exists because God hasn't dealt with it... yet. Oh, but He will. See, God has a dilemma: He hates evil, He loves humans, but humans are evil. We are. Every single last one of us. So, His solution: The Gospel. God sent His Son, Jesus, to live a perfect life as a man. The punishment we deserve for our evil was instead given to Jesus, as He died on the cross. God no longer has to punish us, because He's already punished Jesus.
For the Christian, that means eternal life in Heaven. There will be no evil there. Ever. For the impenitent sinner? Eternity in Hell. God doesn't want that, so He's patient with us (2 Peter 3:9), but even He has His limits. His tolerance for sin is so low that even those who repent of it could not be saved without the death of Christ. How long do you think God will put up with those who refuse to repent? Hell isn't the option God wants, but it is an option He will take if repentance is taken off the table.
This is testament to His goodness. He could destroy all evil, but because He is good, He didn't spare His own Son, and the only condition He has for giving us this gift? We have to receive it. Simply confess Jesus as Lord and believe God raised Him from the dead, and that's it. We have the cheek to accuse Him of creating evil, when He's so good He actually extends grace to evil men? The "problem" of evil is just one more evil men have committed.