Im honest here, If this theory will go trough to the world many people can't take it because it's hard.
But If you know this it makes your mind free, so short and simple you are all your soul will experince all the possible scenarios in order for higher fullfillment of SOULS.
If you are poor now it means you was rich in some other life experinces or you will be.

Based on your actions after the death higher power will judge your life and will give the same experince what you have caused to others. For example: you was ruthless slave trader very brutal person and disshonest then you will be born into bad and poor conditions on your next life experince so you can feel exacly the same experince, for example you did steal a lot from others, well on your next life experinces you will be the one who will have huge loss because of stealing. That's why it's called bad luck, actually it's a bad karma.

Now If you know all of this you think twice what you do, but it's all okay it's all part of process we all learning and some souls are just more mature then others and learning faster and some don't.