One truth related to lessons learnt in the subject of Science in our school days' applies to some core aspects of Christian Living also especially the inter-related Spiritual dynamics of Cross-bearing and Spiritual Growth (Rom 5:3-4).
Now what is that Scientific Lesson??? Well, it pertains to Boyle's Law ...which deals with the volume of Gas in relation to pressure. Boyle's Law says that in the "unseen" Gas, it's volume and pressure are inversely proportional. By the same token the outward bodily welfare and inward spiritual welfare in a Christian's life are inversely proportional. If bodily health is very good, spiritual health may decrease. On the other hand, if outward bodily health is not very good, inward spiritual health will be very good. Similarly pleasant outward circumstances, may not bring as much inner spiritual growth as unpleasant outward circumstances do.
Take the case of Apostle Paul...he declares...
A) In 2 Cor 4:16, when outer man is "perishing", the inner man is being "renewed"
B) Thanks to the "painful thorn in the flesh", his humility (most important virtue in our spiritual walk with the Lord) is being sustained (2 Cor 12:7-10).
So even as we recall some school lessons, let's be thankful to the good Lord for helping us understand the significance of "Spiritual Boyle's Law". More difficult the Cross -bearing (Note: The Wise Lord wouldn't increase the outward pressure more than what we can bear- 1 Cor 10:13), greater our spiritual growth in Christ-like virtues like humility, patience, self - control et al...