Tremendous heat is generated on the exterior of the Concorde airplane when it flies at supersonic speeds. The temperature on the outer surface of the plane can get to 127 C (261 F) even though the outside air temperature is -56 C (-69 F).
The expansion caused by this heat makes the plane 9 inches longer at cruise speed than at rest. The cabin floor of the aircraft is built on rollers and doesn't expand, and four air-conditioning systems keep the inside comfortable. While the outside of the plane is undergoing tremendous stress, the inside climate remains constant.
In today's Scripture, Paul described our "outward man" as perishing under the heat of great pressure, while our "inward man" is renewed day by day. Note the contrast:
On The Outside On The Inside
Pressed on every side Not crushed (v.8)
Perplexed Not in despair (v.8)
Persecuted Not forsaken (v.9)
Struck down Not destroyed (v.9)
When faced with trials, we too can have an inner strength through Christ (v.11). Our part is to look beyond the temporal to the eternal (v.18) and to renew our minds daily (Eph. 4:23) through the Word of God and prayer. — Dennis J. De Haan
Upon your own strength you cannot rely;
There's a fount of strength and grace on high;
Go to that fount, your strength renew,
And the life of Christ will shine through you. --Hopkins
God's Word refreshes our minds; God's Spirit renews our strength.