Peter is commanding us to experience hope. This is the main verb, the main clause, in this verse. Which simply means that girding up the loins of the mind and being sober are means to the end of the main thing, namely, hoping fully. Fix your hope completely on the grace to be brought to you at the revelation of Jesus Christ. When Jesus comes back he is bringing grace to the people of God.
Grace is on the way.
Hope in it. Hope fully in God's grace. This is not a coincidence. In those who hope in his steadfast love. The first human counterpart to divine grace is hope.