John Calvin Commentary Matthew 13:21

"yet hath he not root in himself, but endureth for a while; and when tribulation or persecution ariseth because of the word, straightway he stumbleth." — Matthew 13:21 (ASV)

When affliction or persecution arises on account of the word. By way of example, Christ says that such persons are made uneasy by the offense of the cross. And certainly, just as the heat of the sun reveals the barrenness of the soil, so persecution and the cross expose the vanity of those who are slightly influenced by an indefinable desire but are not actually moved by earnest feelings of piety.

Such persons, according to Matthew and Mark, are temporary,²⁰⁴ not only because, having professed for a time that they are disciples of Christ, they afterwards fall away through temptation, but also because they imagine that they have true faith. According to Luke, Christ says that they believe for a time; because the honor which they show to the Gospel resembles faith.²⁰⁵

At the same time, we should learn that they are not truly regenerated by the incorruptible seed, which never fades, as Peter tells us (1 Peter 1:4). For he says that these words of Isaiah, The word of God endures for ever (Isaiah 40:8; 1 Peter 1:25), are fulfilled in the hearts of believers. In them, the truth of God, once fixed, never passes away but retains its vigor to the end.

Still, those persons who take delight in the word of God and cherish some reverence for it do, in some manner, believe; for they are widely different from unbelievers, who give no credit to God when He speaks or who reject His word. In a word, let us learn that none partake of true faith except those who are sealed with the Spirit of adoption and who sincerely call on God as their Father. And as that Spirit is never extinguished, so it is impossible that the faith which He has once engraved on the hearts of the godly shall pass away or be destroyed.

²⁰⁴ “Temporels, c’est a dire, de petite duree;” — “temporary, that is to say, of short duration.”;” — “temporary, that is to say, of short duration.”

²⁰⁵ “Ressemble aucunement a la foy;” — “somewhat resembles faith.”;” — “somewhat resembles faith.”