1 Peter 1:5

Who are kept by the power of God— The word φρουρουμενους, which we translate kept, is very strong and expressive: it does not mean being kept after any manner, but with the most constant and vigilant care; as a tower or a city is watched by a military garrison, which keeps guard day and night, and plants the greatest number of centinels where the place is weakest, or there is most danger. Such is the watchful care of God over his people: as long as they continue faithful, nothing shall be able to hurt them; no enemies or persecutors can deprive them of their reward. Through faith, δια πιστεως, would be read most properly during faith; and the verse may be paraphrased thus: "who, as long as you steadily adhere to the Christian faith, are guarded and defended by the mighty power of God, and preserved unto that salvation or eternal happiness, which is prepared, and will certainly be revealed at last; that is, at the end of the world:" for at the general conflagration, or when the present state of things comes to an end, then shall the greatest and final salvation be revealed. In speaking of the last time, possibly St. Peter might allude to Daniel 9:13. See John 6:39; John 11:24.