When the body is tried, then the soul is sanctified. With sickness, our body is pained, this mud-built house of ours, but thus its tenant, our soul, will rejoice eternally in the heavenly palace which Christ will prepare for us. With this spiritual logic, which is irrational to worldly people, I rejoice and I am proud for the bodily harms which I have. The only thing that I don't think about is that I will have a heavenly reward.
I understand that I am redeemed from my thanklessness towards God, as I have not returned His great gifts and benefactions. Because in my life, everything has been a feast: I partake of monasticism and my afflictions. All are benefactions which God has wrought, and all mercies. Pray, however, that I not be satisfied with these in this life, because this would be to my woe! Christ gave me a great honor to suffer even further for His love. It is enough that He strengthens me so that I might bear it, and I don't want any reward.
Amateur translation of text from: Elder Paisios of the Holy Mountain, from the book "Passions and Virtues", Volume V. (source)