"Not only so, but we also rejoice in our sufferings, because we know that suffering produces perseverance; perseverance, character; and character, hope. And hope does not disappoint us, because God has poured out his love into our hearts by the Holy Spirit, whom he has given us." -- Romans 5:3-4
For the believer there is great joy in knowing that they have peace with God and are forgiven. But when sufferings come, and they will, how should they respond? They not only press on, but they rejoice in their sufferings finding spiritual qualities growing in their lives. All this is possible only through an inner drive... the Holy Spirit.
Think about this: "Seamen cannot create the wind, but they can hoist their sails to welcome it; neither can we create the breath of the Spirit, but are we to miss it when it comes through failure to keep our sails unfurled?" ~ John Bunyan