Charles Spurgeon Commentary 1 Thessalonians 5:18

"in everything give thanks: for this is the will of God in Christ Jesus to you-ward." — 1 Thessalonians 5:18 (ASV)

For this is the will of God in Christ Jesus concerning you.

God wills it. This moved the Crusaders to the war. Let this suffice to move you in thanksgiving.

In every thing give thanks:

Try to do so for everything, and if you cannot do it, in everything give thanks for something else—when you are in circumstances which do not excite your thankfulness just then.