7 But we have this treasure in jars of clay to show that this all-surpassing power is from God and not from us. 2 Corinthians 4:7

We see jars of clay as a temporary measure because they break easily. When this was written, kings put important treasures into these jars to prevent moisture from rotting them. They couldn’t bury the treasure else the moisture would ruin them, so they put them in jars instead.

The treasure Paul was referring to was “the light of the knowledge of God’s glory” in the previous verse.

Tying it altogether then, God has given us the Gospel. When we “take it out” and use it, it becomes a powerful weapon in the world. If, however, we let it remain inside, yes, it will be preserved but it’s just that, a hidden treasure. The similarities between this and “hiding the light under a lampstand” (Matthew 5:16-16) is appropriate.

So we have this treasure, what will we do with it?