Here in Peter's greeting, he already introduces some major themes for this letter. To the elect temporarily dispersed abroad. This is the identity of the church. Elect aliens. Not necessarily exiled as John will be on Patmos - but alienated, dispersed, far from home. Because for Peter, the elect only arrive back home in the day of our salvation and resurrection. And so Peter begins the entire letter with a very clear statement on these brothers' and sisters' identity as God's chosen exiles - that this is according to the foreknowledge of the Father, by the sanctifying of the Spirit, and for two purposes: for their obedience and for their sprinkling with the blood of Jesus. (These ideas of obedience/godly living and salvation will be held together consistently through the letter.)
And it is here that he introduces another major theme: future hope. Because of God's mercy in salvation, we have been born into a new and living hope - hope in a future inheritance that is right now being guarded for us in Christ. Just as we are being guarded. And the purpose of that guarding - of both the inheritance and the elect - is that they might be revealed in the last time (hence, the future hope). And Peter locates our rejoicing here, in this future revelation. What does that mean for believers in the present? For chosen exiles now? It means that you can suffer grief in various trials. These trials refine your faith like gold; you are being kept and purified just as the inheritance is being kept undefiled and unfading. And all this is being done that it might result in praise and glory and honour bursting out at the revelation of Jesus Christ and the day of salvation. That is the goal and the reward of your faith.
