Christians must long to draw closer to God. If we are quenching our thirst at forbidden fountains, we have no reason to expect God to be satisfying. If we are not nourished by the bread from heaven, we will satiate ourselves with crumbs from the world. Once we have become addicted to the world’s nourishment, our appetite for God is spoiled.
I believe that many professing Christians are cold and uncomfortable because they are doing nothing for their Lord; but if they actively served Him, their blood would begin to circulate spiritually, and it would be well with them.