According to Peter, we ought to bless God because of His great mercy to us in rescuing us through Jesus. He has given us new birth. We may not feel it, but our salvation is an act of God's great mercy. We deserve death, yet He gives us life. We deserve punishment, yet He has achieved a great reward for us. We should bless God that our souls are safe in His hands. That is something that far outweighs all of our slight and momentary troubles. We have a God who has rescued us, even when we don't feel rescued.