1. why is life unfair?
Life is not unfair, it depends on how you use your abilities and what you use them on.
In general, people who think life is unfair is unable to think of a way to live life, or is too lazy to do anything about it.
Life is a constant project to work on, because we are conscious of it being there.
2. why do people get bad luck?
Law of Reality: Life has ups and downs, all balanced in one way or another. Hybris will always come to those who drink too much of the pool of luck, while the sun might shine on you in the darkest hour, simply because you deserve it.
And without the works of my fiction: Luck is where you see it. People might think they are in bad luck, because everything seems to fail, but they are forgetting to look arounf them. Not all luck is like a million dollars, and often you will have to earn it. If you do nothing, do not think you deserve anything.
3.who says that god is one? if there's one, why are there wars? And why are there so many religions? And all the wars are about the religion
God can be many. It depends on the person explaining it. Wicca explains that there is two gods, the masculine and the feminine. The people of the book would say there is one god, and this god is either masculine or nongendered. Hinduism has a lot of gods, while Buddism has none. All could be right, all could be wrong. The different gods could be aspects of one, a higher being that reached Nirvana only to be there to watch the humans.
Sadly no one is interested in this. They only want to be right.
But I have to say one thing: Most wars today is not about religion, but about material things: Oil, land.. Or just proving a point. The holy wars with muslims and christians fighting each other is blasfemious, as they believe in the same god. The crusades was blasfemious because of this.
What about death?
The end of life, maybe the beginning of a new. A travel, even. We will probably never know.
Depending on the religion or lack of same, you can end up many places and in many ways, but who to say which is the right.