Adam Clarke on Revelation 14:12

Here is the patience of the saints - Here the faith of the true Christians shall be proved; they will follow the Lamb whithersoever he goeth, they keep the commandments of God, and are steadfast in the faith of our Lord Jesus Christ. Sometimes ἡ ὑπομονη, patience or perseverance, is taken for the reward of these virtues; the text therefore may be thus understood: Here is the reward of the perseverance of the true Christians; for although they die for the testimony of Jesus, yet they shall be unutterably blessed. See the next verse.