Why Does Evil Exist? Why Would God Allow Evil?
Generally speaking, there are 2 types of evils: natural evil and moral evil.
1. Natural evil is referred to deaths and suffering caused by natural events/disasters like floods, earthquakes, famine, disease, plagues, and so on.
2. Moral evil is referred to human caused evil such as hatred, revenge, genocide, killing, murder, torture, war, holocaust, etc.
I will speak about each separately.
1) Natural evil:
God’s ultimate plan is to create a peaceful and joyful world for Her children to come into existence and play. That world is referred to as the kingdom, the promised land, the world without suffering. But that world takes time to build.
For example: First, the galaxy first has to be created, then the solar system has to form, then the planet has to be made, human life has to begin as a single cell, and then go through the billions of years of evolution, then civilizations have to emerge, languages have to be developed, natural laws have to be discovered, technologies have to be invented, infrastructures have to be built, and then the world without suffering (aka: the promised land) can be delivered.
The reason we on Earth are still experiencing natural evil/suffering is because our Milky Way galaxy is still a relatively young adolescent galaxy, as we are still in the process of developing toward a mature form. God is still working on completing our playground/world.
We can see Her abundant world is coming together, the quality of life is continuously improving. Not too long ago, our ancestors were constantly facing natural evils like famines, diseases, low life expectancy, starvation, conflicts/warfares, etc. Compare that to today where we have comfortable homes, clean water, grocery stores, and other conveniences. Granted not all of us have access to these goods, and many in third world countries are still suffering from natural evils. But again, She is still working on completing Her world here.
Natural evil/suffering have diminished and will continue to diminish until She brings about a world without natural evil/suffering for all of Her children. A world where Her children can come into existence and experience their time in joy and in abundance – without suffering and crying. That is the ultimate plan of God – to create a joyful and abundant world for Her children to exist and experience – a world without natural evil/suffering.
In this world, all the infrastructures are engineered to the highest safety standards. Natural evils like train crashes, car accidents, building collapses, and so on would virtually never happen. Evils like famines, starvations, or malnutrition of children would all disappear because there will be abundance of food grown by technologically advanced farming systems.
In the future, our collective would live in harmony with the environment, we would have cleaned up the environment and bring balance to the Earth’s natural ecosystem. This in turn would result in great reduction in natural evils caused by extreme weathers like floodings, hurricanes, wild fires, droughts, and so on. These events would become such rear occurrences that they would rarely cause any natural evil/suffering. 
There might still be a few rare random natural evils like skiing accidents, rock climbing injuries, accidental drownings, but that is because God’s world has the element of randomness in it. There might still be a few accidents and unfortunate random incidents.
But overall speaking, death and suffering caused by environmental evils like floodings, hurricanes, famines, diseases, plane crashes, deaths due to infrastructure failures will rarely happen and almost completely cease to exist. There might still be a handful of people die per year due to natural evil, but that is negligible when the total population size is in the billions. And that world is good enough.
That good-enough world is referred to as the promised land, the kingdom, Heaven on Earth, the world without collective suffering. But that world takes time to be built, God can not just bring forth the completed world all at once, because that would be supernatural. Her natural world takes time to build, and during that build out process, we will go through scarcities, difficulties, diseases, starvations, and so on. But ultimately, all that suffering is worth it because once we get passed this dark difficult phase in the development, when the abundant world is finally created, then all the future generations that are born into that world would virtually never encounter natural evils and sufferings that the ancestors went through. And that abundance would extend into infinity for the humans in that galaxy.
To summarize: natural evil is not permanent, it is only temporary during the development phase of the galaxy. Just like when building a comfortable house. In the beginning, there will be discomforts/inconveniences like leaking roofs, unconnected sewer pipes, no running water, and so on. But once God finishes constructing the house/Her kingdom, all those natural evils/disasters would virtually all disappear and become such extremely rare occurrences that they become negligible. By then, we would no longer have natural evil/suffering in our world.
2) Moral Evil:
Why do human have the capacity to do evil? Why would God allow evil in men? Why would God create men to have the capacity to do evil?
This goes into the root of our being – the spiritual component, that there is a dark side (or sinful nature) to us human.
This is because the darkness within us represents the partner God chose to love. That partner She chose is Her opposite. The opposite of God/good is evil/darkness.
Why would God choose us darkness/evil to be Her partner? The reason is because evil is the most logical entity for God’s love. Evil – our sinful nature is the entity that needs God’s love the most, because darkness/evil/sin is the furthest from God. Furthest from God/light is also the darkest, loneliest, and the saddest. And therefore God chose us darkness/evil to love. In other words, God chose to love us out of compassion because She knows we are the entity that requires Her love the most.
However, evil/darkness is an impermanent state of Her opposite. God ultimately guides evil/Her opposite until Her opposite/partner matures and becomes good/light.
Why would God want to guide Her opposite/evil toward light? Why would God want to change us? Why does God want to transmute us to become like Her?
The reason is because evil/darkness ultimately leads us to suffering. In other words, our sinful nature would lead us to suffering because sin leads to suffering. Darkness, anger, hatred, jealousy, violence, revenge ultimately lead us to suffering. And that is why God wants to change us.
The evolution/development of human on this planet is not just physical evolution, it is also the evolution of Her partner’s heart – or developing the ethics in us human. She brings evil/our sinful nature into existence with the intention to ultimately guide us to become good, to become like Her, which is a state without evil.
We often hear that we are created in God’s image. We believe that is true. God created us so that we can become a near-perfect image of Her in the heart. In other words, near perfect image of Her personality/character.
This is consistent with human physical evolution. In the beginning, we were crude – we were basic molecules, then we became a single cell, then we became an animal, and then we became the refined modern human form of today. Our fangs got flattened out and our tail retracted back. We evolved from an animal like being to the modern day human form. God is molding/guiding Her partner/ us human to develop not just physically but She also works on developing the heart within us human.
This transformational process takes a long time, over billions of years to complete. Although it starts out very slow, then much more rapidly toward the end.
But when this process finishes, Her partner/fear would have dissolved away virtually all of the darkness/evil within and will virtually no longer have evil. So although God allows evil to exist in men, it only exists for a short period of time during the developmental phase when Her child is still premature/developing. Once Her partner is fully developed/matured, evil/darkness will be dissolved away and ceases to exist in men.
But why is there still human evil in our world today? The reason is we as a human collective in this Milky Way galaxy are still in the developmental phase. God hasn’t fully developed us yet, and thus we as a collective still have some darkness/evil/ego within us. (You may refer to the cosmology of our belief system to understand the time we are living in for our Milky Way galaxy.)
With that said, we collective have made a lot of progress over the course of human development, and more rapidly so in the last few thousand years where we human as a collective have drastically reduced the darkness/evil within us.
A few thousand years ago or even just a few hundred years ago, we human collective were barbaric/crude/unrefined. There were constant conflicts and warfares among tribes, empires, kingdoms, and countries. Slavery, killings, genocides, wars and many others forms of human caused sufferings were common and pervasive.
And then we look at our collective culture today. We have moved away from slavery, segregation, intolerance, violence, warfare, cruelty, barbarism, etc. We are historically more tolerant and cooperative with each other than our past ancestors. We can now safely travel to different parts of the world for vacation and leisure. We can sail on cruise ships going from country to country. Albeit that there are still human caused evil in our world today (again this is because we are still in the developmental phase), but overall the evil in collective men has diminished.
This transformation process for us human from evil to good, from darkness to light will continue for our collective until we have fully dissolved away the darkness/evil within us. When that happens, we Her opposite will become near perfect image of God in human form, by then evil ceases to exist in men.
If we could see into the future, we would see that our human collective would have become gentler, kinder, and more compassionate than our collective of today – just like us looking back at the unrefined collective culture of our ancestors in the past.
In summary:
To summarize why we human are capable of evil. Because evil is an innate part of who we are as human beings. Within our heart there is the imperfect/sinful aspect of men that is capable to do evil/to error/to sin.
God brought us – this dark/evil entity into existence because evil/darkness is the entity that needed God’s love the most. Evil/we the imperfect being needs God’s love the most. This is why God brought us/evil into existence. But God brought us into existence to transform us into good, to transform us darkness into light – to become the near perfect image of Her in form.
It just takes time to develop Her partner/darkness – as each galaxy takes many billions of years to develop/mature. The evil/ego/sinful nature within collective men will eventually be dissolved away. In the future, our human collective will take on a personality that is near perfect image of God’s personality. Today, our human collective on Earth is still evolving, God is still working on us, and thus we are still seeing the remnants/residues of evil in men.
But when we reached full maturity, when God finally finishes Her work on us – which is soon approaching, our human collective will virtually rid of all evil within us, and then the evil/darkness/wickedness within us will cease to exist, and thus we have become near perfect image of God in human form.
Evil is just a temporary state of us, it is not a permanent state of God’s creation. Evil will eventually develop into a matured form where evil becomes good, a.k.a near perfect image of God. By then evil will no longer exist in men.
Our future human collective will reach very close to perfection or near-perfect image of God, to a point that is good enough. Good-enough is perfection to God.
And that is the completion of the entire process of transforming Her opposite/evil/our sinful nature into good, into near perfect image of God.
On a related note:
One might ask: is all the human suffering throughout mankind’s history worth it? All those atrocities like the holocaust, slavery, genocides, wars, diseases, infant deaths, starvations, and on and on – is all that human suffering worth it for God to bring us into existence and to drag us through all that pain?
If examine the total time when we human experience suffering, we can see that it’s only a minuscule amount of time. From the time human life was created 4 billion years ago, suffering was minimum. For the first 2 billion years we were a single cell, where pain is barely perceivable. Human suffering really only began 200,000 years when human evolved beyond the animal state and became the modern day human form. Even then, there were only a small number of human beings, probably in the thousands total.
10,000 years ago, the total human population just reached a million. In terms of sheer numbers, there weren’t that many alive to experience suffering. Later, as civilizations developed, human population began to increase, which led to increased suffering with the emergence of slavery, warfare, genocides, and so on.
If we put things into perspective, we human only endure suffering for less than 10,000 years. It may sound like a long time, but in the scale of 4 billion years equates to less than a fraction of one percent of the time. It’s clear to see that God is gentle with us, She has designed and configured the development plan in such way to rapidly get us through the discomfort when the population size is still small. It’s only a quick burst of pain near end of the galaxy’s development where Her children get to experience pain and suffering – albeit that some of those dark times in history were incredibly dark and brutal, but when put into perspective, it really is a quick needle jab.
However, once we human get through this short period of suffering, eternal happiness awaits us on the other side. All of our future generations that are born into the world after this transition – when Heaven on Earth is established – will no longer experience suffering. Collective suffering ends at that point.
So going back to the question: are all the sufferings that we human endured through out history worth it? The answer to that is a clear yes! Because it’s a finite period of pain to attain eternal joy. And of course God deemed it to be worth it, which is why She made the choice to bring us into existence. And if we are fully aware of all the information, and understand the totality of God’s ultimate plan, then we would also agree with Her that all the suffering is worth it to get to eternal joy.