Jamieson, Fausset and Brown on James 1:12

12. Blessed--Compare the beatitudes in the Sermon on the Mount (Mt 5:4, 10, 11).

endureth temptation--not the "falling into divers temptations" (Jas 1:2) is the matter for "joy," but the enduring of temptation "unto the end." Compare Job 5:17.

when he is tried--literally, "when he has become tested" or "approved," when he has passed through the "trying" (Jas 1:3), his "faith" having finally gained the victory.

the crown--not in allusion to the crown or garland given to winners in the games; for this, though a natural allusion for Paul in writing to the heathen, among whom such games existed, would be less appropriate for James in addressing the Jewish Christians, who regarded Gentile usages with aversion.

of life--"life" constitutes the crown, literally, the life, the only true life, the highest and eternal life. The crown implies a kingdom (Psa 21:3).

the Lord--not found in the best manuscripts and versions. The believer's heart fills up the omission, without the name needing to be mentioned. The "faithful One who promised" (He 10:23).

to them that love him--In 2Ti 4:8, "the crown of righteousness to them that love His appearing." Love produces patient endurance: none attest their love more than they who suffer for Him.