Matthew 13:20-21

As for what was sown on thin (rocky) soil, this is he who hears the Word and at once welcomes and accepts it with joy; Yet it has no real root in him, but is temporary (inconstant, lasts but a little while); and when affliction or trouble or persecution comes on account of the Word, at once he is caused to stumble [he is repelled and begins to distrust and desert Him Whom he ought to trust and obey] and he falls away.