1 Peter 1:5 - Matthew Poole's English Annotations on the Holy Bible

Who are kept: lest it should be objected, that though the inheritance be safe in heaven, yet the heirs are in danger here upon earth, by reason of the power and stratagems of enemies, and their own imprudence and weakness; he adds, that not only their inheritance is reserved for them, but they preserved unto it, kept securely and carefully, as with a garrison, (for so the word signifies), against all the assaults, incursions, and devices of the devil and the world. By the power of God; which power is infinite and invincible, and therefore able to keep them, 1 Thessalonians 10:28,29 Ro 8:31,38,39 2 Timothy 1:12. Through faith; which, resting on the power of God, overcomes all their enemies, the flesh, 1 John 3:9, the devil, 1 Peter 5:9 Ephesians 6:16, and the world, 1 John 5:4. It implies, that not only they themselves are kept through faith, whereby they rely on the power of their Keeper, and his promises of keeping them, but that they and their faith too are kept by the power of God. Unto salvation; viz. full and complete in glory, and not only begun and imperfect here. Ready; as being already purchased, prepared, and laid up for them; and so he intimates, that their not as yet possessing it, is not because it is not ready for them, but because the time of their being put in possession of it is not yet come. To be revealed: it was said to be reserved in heaven, 1 Peter 1:4, kept safe, but close too, as a rich treasure, the greatness of it is not yet known, even to them that are the heirs of it, Colossians 3:3,4 1 John 3:2; here he adds, that it is to be revealed, and made known to them, so soon as the time of its manifestation shall come. In the last time; simply and absolutely the last, viz. the day of judgment, which is called the last day, 1 Thessalonians 6:39,40 1 Thessalonians 11:24 12:48.