who by the power of God are guarded through faith for a salvation ready to be revealed in the last time.
The salvation ready to be revealed in the last time is the aspect of salvation that we have yet to enjoy, namely, our glorification. When God glorifies us, He will save us from the presence of sin forever. This will happen when we see our Savior and are from then on with Him (1 Thessalonians 4:17). This glorification will become ours at death or the Rapture, whichever event comes first.