1 Peter 1:5-7

who by God's power are being guarded through faith for a salvation ready to be revealed in the last time. In this you rejoice, though now for a little while, if necessary, you have been grieved by various trials, so that the tested genuineness of your faith—more precious than gold that perishes though it is tested by fire—may be found to result in praise and glory and honor at the revelation of Jesus Christ.

1 Peter 1:5-7

Coming to verse 5, Peter is talking about those who have been born again.  They are being guarded by God's power.  Maybe it would be better to say they they are being kept safe.  What's interesting is that it is "through faith" that this is happening.  God's power is doing the guarding but this is happening through faith.  This makes me think of Ephesians 2:8.

For by grace you have been saved through faith. And this is not your own doing; it is the gift of God,

Ephesians 2:8

Believers are saved by grace but this happens through faith.  It seems like a very similar thing is being described here in 1 Peter.

What those who have been born again are being guarded for is described as "a salvation ready to be revealed in the last time".  Are those born again not already saved?  Perhaps it is more of a focus on the revealing of this salvation.  Maybe it is described this way because of the trials that Peter's readers were facing.  It only makes sense that he move on to address what he does in verse 6.

Pointing to that salvation to be revealed and God's power that is guarding those born again, Peter says "In this you rejoice".  It is certainly something to rejoice in.  This is particularly important for his readers who "have been grieved by various trials".  Though times may be tough, those born again can certainly rejoice in the power of God is that is guarding them for a salvation that has not yet been revealed but will be revealed.

Peter tells his readers of a purpose for them being "grieved by various trials".  The purpose is "so that the tested genuineness of your faith... may be found to result in praise and glory and honor at the revelation of Jesus Christ".  As NLT puts it, "These trials will show that your faith is genuine".  The result is that your faith will produce an outpouring of praise when Christ is revealed.  It may be tough, but it's worth it in the end.