In terms of religious perception and why someone ends up with an illness and/or disability - some scriptures may be used to qualify the theory that someone with illness and/or disability are being punished for what they continue to do in their everyday lives to bring on 'judgement'. However, my firm belief (in relation to the character of God) is that He is a loving, forgiving God who does sometimes allow us to go through hardships.
"Therefore we do not lose heart. Even though our outward man is perishing, yet the inward man is being renewed day by day. For our light affliction, which is but for a moment, is working for us a far more exceeding and eternal weight of glory, while we do not look at the things which are seen, but at the things which are not seen. For the things which are seen are temporary, but the things which are not seen are eternal."
2 Corinthians 4:16-18
It seems in every society, there exists a notion that the reason someone is ill and/or disabled is simply because the afflicted person has major problems with their soul/spirit or mind and that they are the cause of their own problem. This includes belief that when seeking healing from God, one must keep quiet about one's illness and/or disability - as speaking about it or or not 'keeping our tongue' in line will cause greater problems with one's illness and/or disability.
Some groups believe that other believers are deceived to think that God can use bad situations, terrible situations to benefit His kingdom and His people. That bad situations (in health or other) do not have the purpose to teach and grow and move. The belief also goes on to purport if you are not being physically healed you have a 'blockage' in various areas - 'because, God wants to physically heal everyone' and if the problem is not God (and it's can't be, as God is perfect) - then it must be you.
I BELIEVE THAT THE CORE OF GOD IS (AND SHOULD BE REFLECTED AS) EMPATHY FOR THOSE THAT SUFFER.
For example, anyone who has a 'bad' circumstance happen to them, whether health or other - should not have judgement cast at them - but rather kindness and love. The mental state of anyone also dealing with 'bad' circumstances must also be taken into account and the possibility of this judgement causing further mental trauma to the judged. How does this type of teaching impact on the mental health of those being told they have a 'blockage' - I run from it - however, I also pray for those that believe this.
In all of this perception - we need to stop and ask ourselves 'what is our personal belief system about God & Goodness'? Personally, I believe in Jesus Christ - I do not believe He came into this world and went through a terrible death for nothing - He died for our sin & our disease (physical & mental). I believe God allows illness and/or disability for reasons, we may never understand on this earth.
With all of man's accumulated knowledge, through medical science about why our human bodies do what they do or why disease behaves in such a way - we still don't have all the answers. I believe that our feeble human minds will often try to find ways (using popular perception or even scripture) to explain away or quantify 'the unknowns' about why some people have incredible healings and why some do not. Our brains simply can't take the fact that disease and illness/disability can happen to anyone, at anytime for a variety of physical reasons, including random damage from viruses, DNA injury, acquired disability or even disability/disease we may be born with.
I truly believe that knowledge is power, power is knowledge and ignorance comes from a lack of knowledge. So, in conclusion (& my firm opinion is), illness and/or disability today is NOT caused by spiritual problems/bad luck or karma. NOT AT ALL and telling anyone who has such an affliction is a cruel thing to do to anyone. RATHER, if you don't understand why someone has an illness/disability, make sure you EDUCATE yourself on the disease and/or the disability and understand the everyday suffering and difficulties that person must endure. Remember, we may never understand why we have to endure these things on earth, but I believe that God is in control, regardless.
"I am only one, but I am one. I cannot do everything, but I can do something. And because I cannot do everything, I will not refuse to do the something that I can do. What I can do, I should do. And what I should do, by the grace of God, I will do."