Rayz: He's fair for your spirit, the harder the proof the higher your spirit becomes, you can be handicapped, poor, primitive, but if your spirit passes the test, because that's the reason why some spirits choose harder proofs to reach perfection.
Humans do what God set them to do, to explain it better, what's bad for humans maybe good for animals, the best way i have to explain you this is giving you a link for you to read:

http://www.afterlife101.com/Spirits_Book.html

If you have any doubts afterwards, feal free to ask ;)

Only God Can Judge Me
الله فقط يمكنه محاكمتي

I am you and you are me, if you love i love, if you suffer i suffer
أنا أنت, و أنت أنا, إذا أحببت نفسك أحببت نفسي, إذا عانيتَ عانيتُ