There are people who believe life is predestined. They believe that god knows everything, he know what happened and what is going to happen. Future is in his memory or somewhere else and whatever we are going to do happen according to that. So they believe we are doing what he have in his mind.
If somebody hurt us, then some people consider it was predestined to happen, and if we hurt them back, then also they consider it was predestined to happen. But we don't take things that way at the core of our thoughts. Suppose you were stranded in a desert. You are very thirsty and you saw a tap. You ran towards it and opened it but there was no water in it. You will feel disappointed. It is the way we got shaped in nature. You will not feel there is nothing to worry, it is part of god's plans and everything is alright, initially. But such thoughts might come to you when you accept your situation. You will console yourself thinking it is destiny and my children have their own destinies where they will reach regardless of whether their father is dead or alive. We can clearly see the cause and effect in it. You are thirsty and have no water. You saw a tap and assumed it had water. You got happy because you are finally going to quench your thirst. You reached it and found there was no water. It was contrary to your desire and you got disappointed. Then you began to think that you are going to die. You think it is fate and console yourself believing it. Deep down we think in terms of cause and effect. The thoughts of fate or destiny doesn't come natural to us, we construct it to shield or console ourselves or to explain the feelings that come natural to us.
When a baby dies, people may tell that it is fate. They can't understand what he possibly did to deserve it. They might believe we cannot understand god, god work in mysterious ways. But it is not the reality. It shows their inability to accept or find the real reason. We don’t need to believe in it now, considering how much we know about our environment and its working. Presently we have efficient methods to measure different hormones, chemicals or the presence of microorganisms. We have an understanding about the cause and effect of many things, diseases, natural calamities etc. We are very much in a position to see things in terms of cause and effect but some of us do not seem to be ready to see it the way it is.
We can die of diseases or accidents or because others find us a threat or a nuisance. You were born to your parents and you happen to be of a certain race with a certain color. There is no miracle involved. It is nature taking its course. There are lots of interactions happening between different things in the universe and when we consider the different possibilities of interactions, we can see things as they really are, that is as actions and reactions, or cause and effect. There is no need for any supernatural element to explain what happen around us. We have enough knowledge to explain many of it. The things we don't know, we currently don't know but we may later find out about it. But there is no need for us to settle for false reasoning or misunderstandings.
We know the universe has its laws. We know there are laws of conservation of momentum, laws of gravitation etc. We know our universe works according to these laws. Maybe it didn't work this way for the entire time but as far as we can observe, it is working in a particular fashion. But some people think that the universe work in mysterious ways. They may believe in god, ghost, time travel, immortality or other supernatural entities. They may also believe the universe has to have a creator. They may call the creator god and give him certain abilities, properties or behaviors. But actually we do not know for sure about god, ghosts, afterlife or other such claims. If we apply cause and effect to the universe in a rational way, we will see that we do not know about the cause of our universe. But it is no reason to make up stories or imagine things. We know for certain whatever happens in the universe is the cause of universal laws getting applied to the universe.
If you want to know why things happen, you can either choose to believe in stories or find out its real cause. Believing is easy. Some people choose to take the easy path and they want everybody else to follow them. It is senseless and a problem, and not a solution. Destiny has no place in reality.