The short answer, I believe, is that an eternity of peace, joy and bliss outweighs even an entire lifetime of suffering on earth.
When a woman gives birth she usually goes through an intense period of pain but after the baby is delivered and she holds her newborn child in her arms the joy she experiences totally outweighs the suffering she just had to go through. I believe heaven will be like that. An eternity of joy awaits all those who may have suffered greatly in this finite life if they have accepted Christ as their personal savior. Paul summed it up perfectly in (Romans 8:18): “For I consider that the sufferings of this present time are not worthy to be compared with the glory which shall be revealed in us.” And this glory is what awaits us in heaven.
Even a person with a permanent debilitating disease like Muscular Dystrophy can obtain solace when he reflects on the realization that heaven will one day be his future home. It is important to understand that the reason heaven dwarfs even the most intense earthly suffering can be summed up in the following three words: reality, duration and intensity. First, heaven to the Christian is real and certain therefore we can have complete confidence that we will be there when we die. Second, the duration of our suffering on earth is only temporary where our suffer-free existence in heaven is eternal. And third, while our suffering definitely produces pain here on earth the intensity of our joy in heaven, in comparison, I believe will be off the charts. The great news for someone suffering with a permanent disease is that with heaven looming in their future this disease is only temporary!