I am having a hard time seeing how the Christian spiritual condition has anything to do with our physical body (and vice versa). If the physically corrupting nature of sin (like lust, greed, selfishness etc.) affects our spiritual condition, shouldn’t the process of a purified spiritual condition (one redeemed by Christ) affect our physical world, like becoming physically healthier? Or are they just not related?
Sin is not “physically corrupting” necessarily. What passage of scripture tells you that sin is “physically corrupting”? Of course, some sins ARE physically corrupting, such as drunkenness, but other sins, such as greed, are not necessarily physically corrupting. They are spiritually corrupting (and emotinally corrupting as well), but not physically corrupting. So, the premise you base your question on is false, in my opinion, which makes answering your question difficult.
I think the opposite applies as well. I see no promise that, in general, doing good deeds or avoiding sin will have a positive physical effect on our bodies. Of course, certain good deeds and avoiding certain sins will have a positive effect on our bodies, but I see no promise in the Bible that if we obey God our bodies will somehow improve. I would need a scripture to support the idea that this is a promise of God, but I know of none.
There are some who teach the “gospel of prosperity.” They teach that if we obey God we will be rich and healthy, but I do not see that in the Bible. Jesus obeyed God and he never got rich and his obedience ended up getting him killed. All of us will die eventually, and being sick is NOT evidence of sinfulness at least as far as the Bible teaches. That is how I see it.