This body belongs to Krishna and therefore we must always keep it in healthy condition to the best of our ability, but if due to some past sinful activities, we are suffering some bodily miseries we should not become discouraged. Devotional service must continue under all circumstances. This material body is actually a bad bargain because it is prone to suffer, but we must make the best use of this bad bargain. That means to always be engaged in the service of Krishna without fail.

From Srila Prabhupada’s letter to Viruha — Vrindaban 19 April, 1975