This is such a complicated subject. I could go on for a hundred pages, but I will try to keep this short.
First of all, the Humans do not KNOW for sure ANYTHING about the universe. they have beliefs which are held by alot of people, but untill they have been there and experienced everything it has to offer, they KNOW nothing. You cant learn all about something just by looking at it, and thats all we have done besides the moon landing.
There has been absolutely NO evidence proving ANYONE has a soul. We have scanned the human body with every tool we have, and there is no soul to be found. We may find it later, but as of now, there is no proof what so ever.
Death can be explained fairly simply. Do you remember what it felt like before you were born? Thats what after death will feel like. Nothing.
If god exists, then what created god? What created the thing that created god? There is no beggining of time, nor an end of time, as time is infinte. You can ask the question what created this, and what created the thing that created that, an infinite number of times, therefore, there is no such thing as a begining, or at least comprehendable by humans at their current state of mind.
Things to understand. Think of the things to become learned, as an ocean with no end on any side. Think of human understanding as an island that is growing. No matter how much the "island" grows, it will never cover the entire "ocean" as the ocean is endless. There is no limit to the things to understand in the universe.
Part of me, wants to believe in a god, so that in the end, we know everything is going to be ok, and someone is here for us forever, but part of me doesnt think that way, and just wants to continue learning about things and doesnt believe some all knowing being can possibly exist.