Well, we will never know exactly why anything is done by God...he tells us everything we are supposed to know in the BIble...but as far as my personal belief for this question goes...

I beleive that each and every one of us is brought into this world for a reason. We aren't alike...we are unique. We are according to how God wants us to be. From our brain to the color of our eyes to the length of our legs...we are how God made us. I have an autistic child, and though sometimes it's very hard to see her inability to form social bonds, as in having any friends, and fully understanding day to day living, I believe that this is exactly how God wanted her to be. See, though it's tough for us, these children were made this way....they don't have a problem with thier disabilities, WE have a problem with thier disablities....and I also believe that sometimes people are made with these disablilties for US. So that we can look inside ourselves at times, so that we can be thankful sometimes, so that we can have empathy and sympathy and love and acceptance, etc etc. I know in the past I have sat and thought "I wish my leg wouldn't hurt from walking", and then I am reminded by seeing someone in a wheelchair without legs, just how thankful I should be that I have the ability to walk and have a hurting leg. I might have thought "I wish the kids weren't being so loud!", and then I am reminded of someone who would love to be able to hear that can't. I will complain about certain things, but it never fails that I am shown someone that has severe abnormalities or disablities that would be glad to have the problems I have complained about.

The bottom line is, we are all here for a reason. We are all how God wants us to be. Black, white, Asian, short, tall, plump, thin, smart, not so smart, abled and diasabled....Just think, how boring would it be if we were all alike?