If you are asking the cause it is the Pride and Greed of humans.
Greed and pride are responsible for most of humankind's problems.
War? Sometimes pride, sometimes greed.
Jobs going overseas? Mainly greed.
Low quality and dangerous products, illegal drug sales? Mainly greed.
Corrupt politicians? Mainly greed
Corruption and dishonesty in the work place? Mainly greed
Now consider many religious leaders (not all of them of course). Are they Prideful? Have they hoarded vast amounts of wealth? Do they live in palaces? Do they think the are above the laws of men?
I am sorry if I depressed anyone. If you are depressed from reading the above please look at the following picture of a kitten sleeping on a ball of yarn and you should feel better: