“If God is all-powerful and all-good, it would have created a universe in the same way it created heaven: with free will for all, no suffering and no evil. But evil and suffering exist. Therefore God does not exist, is not all-powerful or is not benevolent (good). A theodicy is an attempt to explain why a good god would have created evil and suffering. The most popular defence is that it is so Humans could have free will. However the entire universe and the natural world is filled with suffering, violence and destruction so any Humanity-centric explanation does not seem to work.”
An attempt to justify the existence of evil is to say that God is testing us in some way. Perhaps that if we pass the test(s), God will put us in heaven. Otherwise we remain on Earth or go to Hell. Most religions have similar mythologies. The authors of the Christian Bible included examples of people being tested by God. In Buddhism such tests eventually lead us to Nirvana, in Islam the test is one of obedience to God, success takes you to Paradise. In the Qur'an, suras 47:29-33 is one example where the test theodicy appears to be endorsed: in those verses, God makes clear (asides from the Qur'an being littered with statements that God is omniscient) that it knows specifically which people have failed, and it could, if it chooses, show them out to everyone. But, all people (especially the faithful) are tested, and those who do well are properly rewarded.
God is all-knowing. It knows everything, future and past. This is the omniscient monotheistic God. Such a God exists outside of time, and can see all future and past events as if they've all already happened. This chain of events has all been created by God, from beginning to end. God is immovable, immutable, beyond time. As a result of all this, God clearly knows what tests we will pass and fail. God knows if we are largely moral or largely immoral. It knows why we transgress, and it knows in detail every reason and factor that ultimately causes us to go wrong.
God therefore never needs to test anyone. God knows, even without doing a test, what the results of the test will be. Let's say God wants to test someone by allowing them to stumble across a wallet in the street with money in it. Let's assume that God considers it best if the subject hands the wallet in to the police, and worse if the subject steals the money and throws away the wallet. God knows if the person will pass such a test. God knows it because it created the person and their personality in the first place, so can work out what they will do. It also knows what the person will do because it is all-knowing, and knows all possible future events. God never needs to actually test the person, God already knows if they'll pass. To say that God needs or wants to "test" us is to say that God is not all-knowing.
The existence of suffering and evil, therefore, is clearly not excused by saying that God wants to test us. God knows, if it creates evil, who will pass its tests and who will fail. God doesn't need to actually create evil, suffering or unhappiness to know who will fail. Likewise, God does not need us to make moral choices in order to know if we're moral or not. God knows what we would choose if moral options are presented to us. The actual testing is not required because God already knows. Therefore the 'test theodicy' cannot be used to explain why god created evil.
God could have created a world with no evil, no suffering, and no moral confusions. That way, everyone would be happy all the time, and we would rightly know that a loving God existed. God would still know, if it allowed transgression and evil, who would succumb to temptation and who wouldn't. But the actual creation of potential evil is not necessary. As it is clear that suffering exists and moral dilemmas abound, we know that either God is evil or doesn't exist. We certainly know that evil, confusion, suffering and anything else is not a "test" from God.
Some people will pass the test. Given that God knows who will pass and who will fail its tests, and therefore who will get into heaven, what's the point of Earthly existence at all? God knows who will, in the future, deserve to enter heaven. So why doesn't God, with its knowledge, simply put those people into Heaven now? It could do so, if it wanted. Nothing would be lost. Suffering would be reduced, free will would be unaltered.
Some people will fail the test and will be punished with hell. God knows, from even before the time when a person is born, whether or not they will pass its tests and enter heaven. Why then does God bother to create people who are to fail these tests? What's the point of the testing when it already knows the answers? Why not simply put those who will fail into hell, those who will pass into heaven, and not have to bother with all the confusion inbetween? More importantly, why does God create people who it knows are going to fail and then suffer torment in Hell? It seems that if there is an all-knowing perfect and just God, it would look at all the people who freely chose the wrong actions in life and it wouldn't create those people. This way, those people wouldn't need to suffer in hell.
In other words, God looks at the future fate of all people. Those who freely choose good are created in heaven, where they don't have to suffer during an Earthly life. Those who freely choose evil are not actually created. Therefore everyone who God creates are those people who freely chose to do good in life. This way, there is no need for suffering, pain, angst or evil in the world.
Sometimes, it is said in the Bible that God tests people. In Deuteronomy 8:1-2 God reveals that the 40-years in the wilderness was a test done by God to find out what was in people's hearts - whether they would still obey orders. In Deuteronomy 13:1-5 God sends some false prophets and wonder-workers as tests to see if people will follow other gods, and in 2 Chronicles 32:31 God is doing similar fact-finding tests. In Genesis 22:1 God tempts Abraham, and Job lost everything as part of a horrible series of tests done by Satan and God in collaboration, of Job's loyalty to God. Yet an all-knowing God, creator of all time, knows exactly who will pass any tests, and knows exactly what is in everyone's heart. So either God is lying about his reasons, or, god is not actually all-knowing. Strangely, in James 1:13 it says that no-one can say that God has tempted them with evil, because "God tempteth no man". These contradictions to logic, and, contradictions to other verses, clearly indicate that the authors of the Bible did not have a particularly good grasp of theology or philosophy, and could not have been inspired by God to write what they wrote!
“To the present day, all theodicies have failed to explain why a good god would create evil, meaning that the existence of evil is simply incompatible with the existence of a good god. After thousands of years of life-consuming passion, weary theologians have not formulated a new answer to the problem of evil for a long time. The violence of the natural world, disease, the major catastrophes and chaotic destruction seen across the universe and the unsuitability of the vastness of reality for life all indicate that god is not concerned with life, and might actually even be evil. Failure to answer the problem of evil sheds continual doubt on the very foundations of theistic religions.”
The Bible (NIV). The NIV is the best translation for accuracy whilst maintaining readability. Multiple authors, a compendium of multiple previously published books. I prefer to take quotes from the NIV but where I quote the Bible en masse I must quote from the KJV because it is not copyrighted, whilst the NIV is. [Book Review]