What does 1 Thessalonians 3:5 mean?

That's why, when I couldn't take the worry anymore, I sent Timothy to find out how your faith was holding up. I was afraid the tempter might have gotten to you and all our work would have been for nothing. 1 Thessalonians 3:5 - Modern Text Bible

(Paul was genuinely anxious that their faith might have been undermined by hardship or temptation, and he needed to know they were okay.)