Passage
Prove all things; hold fast that which is good.
Prove all things; hold fast that which is good.
1 Thessalonians 5:19 Quench not the Spirit.
1 Thessalonians 5:20 Despise not prophesyings.
1 Thessalonians 5:21 Prove all things; hold fast that which is good.
1 Thessalonians 5:22 Abstain from all appearance of evil.
1 Thessalonians 5:23 And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ.
The verse centers on "all things", "prove", "hold", "fast", and "good". It is saying that the verse draws attention to "all things" and "prove", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 20's "Despise not prophesyings..." into verse 22's "Abstain from all appearance of evil...", so "all things" and "prove" belong inside that flow. In 1 Thessalonians context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "all things" and "prove" with trust shaped by these words, not by a vague optimism outside the passage.