Matthew 13:21

Yet hath he not root in himself
Nor in Christ; the word is not rooted in him, nor has he the root of the matter, or the truth of grace in him:

but dureth for a while;
a hearer of the word, a professor of religion, showing some outward respect to the word, and to the preachers of it:

for when tribulation or persecution ariseth, because of the word;
which is often the case, and must be expected by those who embrace the Gospel, profess the name of Christ, and are willing to live godly in him. Tribulation may intend some lesser and lighter troubles for the sake of Christ, and his Gospel; such as the revilings and reproaches of men, loss of character, and trade and persecution may design something more public and vehement; such as confiscation of goods, imprisonment, and danger of life, the most exquisite tortures, and death in the most cruel form and shape; things very disagreeable to flesh and blood, and which cannot be endured, and submitted to, by persons without a principle of grace, by one that has no root in himself. Luke calls this a time "of temptation", or trial, as it is either way, both by private troubles, and more public persecutions: these try men's principles and professions, and whether the truth of grace is in them or not; and where it is not in any person,

by and by he is offended;
at the cross; he shrinks back from it, does not care to take it up, and follow Christ; but drops his religion, and the profession of it; apostatises, falls away, and comes to nothing.