Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
(Rev 21:1-8) A new heaven, and new earth: the new Jerusalem where God dwells, and banishes all sorrow from his people.
(Rev 21:9-21) Its heavenly origin, glory, and secure defence.
(Rev 21:22-27) Its perfect happiness, as enlightened with the presence of God and the Lamb, and in the free access of multitudes, made holy.
The new heaven and the new earth will not be separate from each other; the earth of the saints, their glorified, bodies, will be heavenly. The old world, with all its troubles and tumults, will have passed away. There will be no sea; this aptly represents freedom from conflicting passions, temptations, troubles, changes, and alarms; from whatever can divide or interrupt the communion of saints. This new Jerusalem is the church of God in its new and perfect state, the church triumphant. Its blessedness came wholly from God, and depends on him. The presence of God with his people in heaven, will not be interrupt as it is on earth, he will dwell with them continually. All effects of former trouble shall be done away. They have often been in tears, by reason of sin, of affliction, of the calamities of the church; but no signs, no remembrance of former sorrows shall remain. Christ makes all things new. If we are willing and desirous that the gracious Redeemer should make all things new in order hearts and nature, he will make all things new in respect of our situation, till he has brought us to enjoy complete happiness. See the certainty of the promise. God gives his titles, Alpha and Omega, the Beginning and the End, as a pledge for the full performance. Sensual and sinful pleasures are muddy and poisoned waters; and the best earthly comforts are like the scanty supplies of a cistern; when idolized, they become broken cisterns, and yield only vexation. But the joys which Christ imparts are like waters springing from a fountain, pure, refreshing, abundant, and eternal. The sanctifying consolations of the Holy Spirit prepare for heavenly happiness; they are streams which flow for us in the wilderness. The fearful durst not meet the difficulties of religion, their slavish fear came from their unbelief; but those who were so dastardly as not to dare to take up the cross of Christ, were yet so desperate as to run into abominable wickedness. The agonies and terrors of the first death will lead to the far greater terrors and agonies of eternal death.
God has various employments for his holy angels. Sometimes they sound the trumpet of Divine Providence, and warn a careless world; sometimes they discover things of a heavenly nature of the heirs of salvation. Those who would have clear views of heaven, must get as near to heaven as they can, on the mount of meditation and faith. The subject of the vision is the church of God in a perfect, triumphant state, shining in its lustre; glorious in relation to Christ; which shows that the happiness of heaven consists in intercourse with God, and in conformity to him. The change of emblems from a bride to a city, shows that we are only to take general ideas from this description. The wall is for security. Heaven is a safe state; those who are there, are separated and secured from all evils and enemies. This city is vast; here is room for all the people of God. The foundation of the wall; the promise and power of God, and the purchase of Christ, are the strong foundations of the safety and happiness of the church. These foundations are set forth by twelve sorts of precious stones, denoting the variety and excellence of the doctrines of the gospel, or of the graces of the Holy Spirit, or the personal excellences of the Lord Jesus Christ. Heaven has gates; there is a free admission to all that are sanctified; they shall not find themselves shut out. These gates were all of pearls. Christ is the Pearl of great price, and he is our Way to God. The street of the city was pure gold, like transparent glass. The saints in heaven tread gold under foot. The saints are there at rest, yet it is not a state of sleep and idleness; they have communion, not only with God, but with one another. All these glories but faintly represent heaven.
Perfect and direct communion with God, will more than supply the place of gospel institutions. And what words can more full express the union and co-equality of the Son with the Father, in the Godhead? What a dismal world would this be, if it were not for the light of the sun! What is there in heaven that supplies its place? The glory of God lightens that city, and the Lamb is the Light thereof. God in Christ will be an everlasting Fountain of knowledge and joy to the saints in heaven. There is no night, therefore no need of shutting the gates; all is at peace and secure. The whole shows us that we should be more and more led to think of heaven as filled with the glory of God, and enlightened by the presence of the Lord Jesus. Nothing sinful or unclean, idolatrous, or false and deceitful, can enter. All the inhabitants are made perfect in holiness. Now the saints feel a sad mixture of corruption, which hinders them in the service of God, and interrupts their communion with him; but, at their entrance into the holy of holies, they are washed in the laver of Christ's blood, and presented to the Father without spot. None are admitted into heaven who work abominations. It is free from hypocrites, such as make lies. As nothing unclean can enter heaven, let us be stirred up by these glimpses of heavenly things, to use all diligence, and to perfect holiness in the fear of God.