Actually this is a good statement.If there is a God, he had better have a good explanation for why one of my closest friends has both high-functioning autism and a paralytic disorder.
I am assuming you don't believe in a God or at least don't understand why these things happen to people, when it is not their fault in anyway.
I could use scriptures here if you like. But I will first just answer it in my own words. As short as I can.
The first thing is God is not ruling the earth at this time. Satan and man both went against God, and so we live in a world that is run by Satan and is imperfect in mind and body. ( how this came about , and why, are explained in the bible but it is a big study, so I will just keep it simple here)
So imperfections are in all of us and in some worst than others. Satan doesn't care about man, just about himself. ( this is about free will)
God original purpose was to have perfect people living on the earth, in paradise conditions. So there would be no, sicknesses or health conditions like you mentioned here.
This purpose of God has not changed. It is still going to be carried out. Just like he purposed, in the beginning.
Because man and Satan had free will, this question of who man will follow Satan or God had to be answered at some point. This is what we are in now. But this temporary, things will change.
So what does this mean for people that have really no chance for life or were killed in accidents and all the other situations. There have been people all through history than really never had a chance to know of a God , or were killed or died from sicknesses.
The promise God gives is that all people that have died, will be resurrected to this earth,( just as the original purpose was), but they will be raised up without all the health problems etc.
Many of the churches teach that you go to heaven, that is not a bible teaching. ( there are a few that go, but these are only for ones the will be part of the ruling class) People were created for the earth, and that's were they are resurrected to. So all people whether they knew who God was or followed him or not, because they have died , they will be alive again on this earth.
That means you will see parents and grandparents etc again. ( That is why Jesus did resurrections on the earth when he was here) It was to show he was able to do it.
This also means there is not a hell were people that are bad go to. That also is false teaching of Christianity. When you die you are dead, no thoughts or anything, there is not spirit that goes anywhere or anything like that.