1 Thessalonians 3:4-5; Luke 8:13

4 For indeed when we were with you, we kept telling you in advance that we were going to suffer affliction; and so it came to pass, as you know.

5 For this reason, when I could endure it no longer, I also sent to find out about your faith, for fear that the tempter might have tempted you, and our labor would be in vain.

13 "Those on the rocky soil are those who, when they hear, receive the word with joy; and these have no firm root; they believe for a while, and in time of temptation fall away.