God is in Charge of the Prenup.

By his great mercy he has given us a new birth into a living hope through the resurrection of Jesus Christ from the dead, ⁴and into an inheritance that is imperishable, undefiled, and unfading, kept in heaven for you, ⁵who are being protected by the power of God through faith for a salvation ready to be revealed in the last time.

The new birth and the inheritance are being protected by the power of God.  Peter has seen it, living through the resurrection of Jesus Christ, living under the blessing.  The new birth is a new life in Christ.  The inheritance is the eternity of that new life.  

The power of God protects them, but the mercy of God is what granted them in the first place.  They may be understood as something being kept in heaven until some future point in time, protected by the power of God, but through faith.  Faith is our part of the bargain. 

This is the change.  In previous relationship agreements-kind of "divine-human prenuptial agreements"; in bible-lingo the term is ‘covenant’-in previous covenant agreements between God and humanity, our end of the bargain was dependent on our behavior.  Do good, get blessed.  Screw up, get cursed.  It works very nicely with the geography of Israel, because the land of Israel is dependent on rainfall. 

There is imagery throughout the Old Testament of God sending the blessing of rain when they behaved, and turning off the tap when they didn’t.

But that didn’t work.  Such covenants linked faith with actions, doing and believing the right thing, and blessings followed.  But people began to assume their actions gave the blessings, they turned faith upon themselves.  Comfort carried them away from the God who cared for them.  So punishment would come, the people would get their acts together, realize the true giver of their blessings, and there would be another round of covenant, until that too slipped away.

This time, the prenup is in God’s power, by the resurrection of Christ from the dead.  It begins with faith, a faith in the reality that Jesus died so we don’t have to.  And actions, instead of being required first, now follow from the faith, actions of gratitude so that we will never forget where the blessings came from.  Thank you Lord for straightening us out.