If God created everything, God must be evil, because evil exists. At least, this is one argument that atheists like to use. But this argument actually springs from a misunderstanding of what evil actually is.
Evil is not actually a thing that exists. You cannot bottle it, you cannot cut it, you cannot bend it, you cannot measure it, you cannot weigh it etc. God did not create evil because evil was not created. Rather, what God made was an initially perfect creation (Genesis 1:31; Deuteronomy 32:4). There was no evil in the original creation. Even Satan, when he was created, was actually good (Ezekiel 28:15).
So, whence commeth evil? Let's zoom in on Satan a little, since I mentioned him initially being good. Satan was initially good, Satan is now evil. So, what changed? What changed is that Satan was no longer content to be just an angel. Satan decided he wanted to be more than an angel; he wanted to be like God Himself (Isaiah 14:14). But Satan was not designed to be God, nor was Satan designed to be like God. Satan was designed to be Satan. He was a wise, beautiful, musical cherub. But Satan eventually decided not to do what he was designed to do and instead do what he was not.
Humans, being free willed creatures, fell for the same trap. We were designed to be image bearers of God and have dominion over His creation, and no further. We were not permitted to eat of the tree, and disobedience to that command was evil brought about by our own free will.
But if free will causes evil, isn't that still God creating evil? No, because free will itself also has a good purpose. Doing good of our own free will is better than doing good out of programming. It does have the disadvantage of allowing us to choose evil, but the intent is allowing us to have a more meaningful relationship with God than a mindless robot.
Thus, God did not create evil. Free willed agents chose to do evil in direct opposition to the will of God. These wrong choices are called sin, and we will ultimately all be judged for it. However, God is not the kind of God to just throw all of His disobedient creations in the bin. Instead, He provided a way out. Jesus, the Son of God, was born of a virgin, lived a perfect life free of sin, and was crucified, taking the just punishment for your sin. He then rose from the grave, allowing all mankind to be reconciled to God. All it takes is faith. Will you come to faith in Him and be forgiven for your sins?