There are many mysteries shown to us in the gospel. Mysteries are truths that were utterly unknown before but later made known in the gospel. One of these is that the saints living at our Lord's Second Coming will not die, but be changed, and that this change will be made in a moment, in the twinkling of an eye, and at the sound of the last trump. This trumpet call is the loud summons of all the living and all the dead, to come and appear at the tribunal of Christ. At this summons the graves shall open, the dead saints shall rise incorruptible, and the living saints be changed to the same incorruptible state. The reason for this change is that this corruptible body must be made incorruptible, this mortal body must be changed into immortal, so that man may can enjoy the happiness designed for him.
When this change of the living and dead in Christ has been achieved, it shall be brought to pass the saying, Death is swallowed up in victory (Isaiah 25:8; 2 Corinthians 5:4). Death will be perfectly subdued and conquered, and the saints will forever be delivered from its power. They will glory over death as a vanquished enemy, and insult this great and terrible destroyer: "O death! where is thy sting? And, O grave! where is thy victory? But how was the victory over death procured? To answer this question, Paul first disclosed the source of death’s power to hurt man. He said, “the sting of death is sin.” That is, it is sin that gives power to death to hurt and kill. It is sin unpardoned, and nothing else, that can keep any person under the power of death. And the strength of sin is the law; it is the divine sanctions against the transgressors of the law, the curse there pronounced, that gives power to sin. Sin is the parent of death, and it is sin that gives death all its hurtful power. Next, he gave the credit for the victory of the saints over death to Jesus Christ (vv. 56-57). Although the sting of death is sin, Christ, by dying, has taken out this sting. He has made atonement for sin; he has obtained remission of it.
Also, although the strength of sin is the law, the curse of the law is removed by Jesus becoming a curse for us. Therefore, sin is deprived of its strength and sting, through Christ, that is, by his incarnation, suffering, and death. It is due to the grace of God in Christ that sin is pardoned and death disarmed. It is by the grace of God, through the redemption which is in Christ Jesus, that we are freely justified (Romans 3:24). It is no wonder, therefore, that this triumph of the saints over death resulted into thanksgiving to God: Thanks be to God, who giveth us the victory through Christ Jesus, our Lord, v. 57. The way to sanctify all our joy is to make it lead us to give praise to God. We can only enjoy our blessings and honours in a holy manner when God is glorified because of it, and we are free to give it to him. Those who remain under the power of death can have no heart to praise; but such conquests and triumphs will certainly tune the tongues of the saints to thankfulness and praise-praise for the victory and for the means whereby it is obtained (it is given of God through Christ Jesus), a victory obtained not by our power, but the power of God; not given because we are worthy, but because Christ is worthy, and has by dying obtained this conquest for us. This circumstance must endear the victory to us, and heighten our praise to God.