a good explanation. simple but rather deep.
I was in searching of answers for these questions about 5 years ago. It was torture for me. I felt I had to find my own vision and perception of the world and life, but it's really hard to do by yourself.
Soon the world gave me a great hint. It showed me the way where to move and find all replies I needed. And I found them;)
We must trust in our own Divine Power and let it lead us in life. It's not so easy as it can seem, but it gives great results! (I don't mean religion now)