who by the power of God are guarded through faith for a salvation ready to be revealed in the last time.
I do not believe the apostle meant that the elect will inevitably continue in faith, namely, continue to believe the truths of the gospel. Paul warned that Christians can stop believing the truth (e.g., 1 Timothy 4:1; 2 Timothy 2:17-18). Rather Peter meant that God’s power keeps believers saved in spite of their sins because we have placed saving faith in Christ in the past. In this sense we never lose our faith.