There is no soul. There is no heaven, no hell, no God or gods, no Devil, no afterlife, no reincarnation. The soul is an ordering, an arrangement of pathways in the brain, not a thing itself. It is as much a thing as the flame on a candle. When you die your soul ceases to exist.
Your soul was created by your body gradually, for the purpose of making your body useful. Your body was created by your parents. If you want to know why your body exists, go ask them. They might have had a reason. They may have a plan for your life too. They aren't omniscient, and they aren't infallible, but they are more experienced than you, and they have similar abilities, so you should take what they have to say seriously.
Parents out there, you get to choose what children to create, mostly by who you marry and whether you have kids and how many and to some degree by how you raise them. A good rule of thumb is that if your parents went to the effort of raising n children, they deserve 2n grandchildren, so you and your siblings can decide amongst yourselves how to get that done. If you're doing OK financially and you're willing to raise kids, then you're probably the one who should be having more than two kids.
Your body was created first, along with its potential abilities and inclinations. Your soul was created gradually by the body and the long arduous experience known as childhood. The main goal of childhood is to produce an able body and a soul who can make good use of that body. The question "how come I have the body I have?" is backwards, because the body comes first. The real question is why your body developed the soul it has, and whether that soul could improve its habits to make better use of that body.
Incidentally, that means abortion is just fine. It's saying that you don't have the resources to bring a child to completion. Or that the child can't ever become an able body and mind no matter how much you invest so you're best off cutting your losses and trying again on a different body. Christianity says the entire worth of a person is present at conception, so abortion is full fledged murder. I strongly disagree. All the potential is there in eggs and sperms, they are easy to come by. It's really only the work the parents have invested so far that is lost if a child dies early. Bodies are the thing; souls are just an emergent behavior of bodies.
There is no Karma (Karma is like a bank account where you get what you give). At least not in the sense of being carried forward from previous lives. There were no previous lives. The closest thing to Karma is money. Your bank account is a measure of society's respect for you; it says society is willing to do this much work at your request. Money isn't very close today, though. Most money comes from interest or capital gains, which are unearned. Rather than saying you should measure your achievements by your bank account money, I'm saying we should adjust fiscal laws to make money act more like Karma.
Reputation is also somewhat like Karma, except that
The universe operates by the laws of physics. It's as old as science says it is (13 billion years old). It doesn't think, and it doesn't care. But we do think and we do care.
I think intelligent actions are the best and most important thing in the universe. I want to have more of them. The universe has no purpose. Life has purpose, but usually isn't very intelligent. People both have purpose and intelligence. Computers can apply intelligence far better than humans, but they only do exactly what people tell them to do, and they don't tell themselves what to do, they have intelligence without purpose.
It is an honor for me to be granted control of my body. I should make my body accomplish as much as it can in the approximately 80 years it will exist. I should change who I am if I'm not controlling my body as well as it could be controlled. I should allow other people to control their own actions too, as best as they are able to, because I want everyone to succeed, and if they have the same philosophy as I do, they need to be able to control their actions in order to succeed.
The abstraction of a soul is a good one. If we could separate the soul from the body, so the soul could live forever and jump from one body to another, that would be a good thing. And the soul can be broken down into memories, plans, habits, goals, the time and energy to think, the right to take action, and so forth. All those might get separated someday. But today a body is one indivisible package and they only last about 80 years.
I think it's better to measure your impact by people-hours you affect, rather than how long your work stays relevant. Aiming for the future still works, it's just not the only way to succeed. By person-hours, pleasing 1 million people for an hour is about equal to pleasing one person for a hundred years (because there are about 10000 hours in a year an 100*10000 is 1 million).
One of the easiest ways to be useful is to be the best in the world at something. This is almost always possible, if you pick a narrow enough field for yourself. I've found a good strategy is to start with really narrow fields, then conquer neighboring fields. If you're the best in the world for just a short time, that's can be OK, provided you have wide impact during your reign. (Web pages are great for getting the word out.)