Time marches on and our time is short in this world, whether it be that our life is but a vapor in the reality of eternity, or the soon coming of Jesus and the end of the age.
Jesus is coming soon, and the definition of soon, is different for us than it is for God.
No matter how long we have, the fact remains our time is limited.
Peter understood his life was soon coming to an end, because of the prophecy of Jesus regarding his eventual martyrdom.
Because of this awareness, and the understanding that after we turn to Christ, He leaves us here for a purpose before calling us home when our purpose on earth is complete.
Until that time we are to make the most of the time we have.
Peter tells us the mindset and attitude we must have while we are waiting for our time on earth to end.