I was asked recently to answer a question on Quora about serious illness, and how it affects the individual and family. So I wrote this:
He goes to a staret (like a Russian priest), tells his story and asks what he should do. The staret says, "Say, Lord Jesus Christ have mercy on me 300 times a day."
He does this. A week goes by, he goes back to the staret. "I have done as you asked, but nothing has changed. I am very hungry. Now what should I do." The staret answers, "Say, Lord Jesus Christ, have mercy on me, 1000 times a day."
This goes on and on, until finally he is up to saying it 12,000 times a day. He finds it is not only taking him all day to say this, but he has found a job, a home, friends, had plenty to eat and his life has completely changed.
It is essential to have a firm spiritual belief to be truly happy. And it helps to believe in reincarnation and the laws of karma. If you are able to do this, then the world will make sense.
As the Buddha said, if you want anything, you will suffer. So if you have an illness and want to be cured, you will suffer. How to fix this - the wise man accepts whatever he gets (from the Bhagavad Gita). So the secret is to SURRENDER and accept what happens.
Ghandi, in his lifetime, wanted to achieve DESIRELESSNESS. Which is saying the same thing.
One might not be happy with what occurs in this life, but if s/he accepts the situation it will be a good learning experience. The secret is to constantly repeat the name of God, whatever that is to you. And everything will work out.
Richard Alpert, a.k.a. Ram Dass, a Harvard professor, went to India and asked his guru many questions over a period of time. He stated he only ever received 3 answers to any question he asked: "Love everyone, serve everyone, and remember God." One needs do nothing else.
If one doesn't believe in God, well, shit happens... and you're screwed.