They Are Not To Forget That Chastening Is Good When It Is At The Hand Of A Loving Father (Hebrews 12:5-11).
And in as far as they are called on to suffer affliction and tribulation, to experience discomfort, hardships and deprivation, they are to consider what God's purpose is in such things. They are to recognise that they are actually for their benefit. For tribulation produces patient endurance, and patient endurance produces experience, and experience produces hope, and all this results in our being unashamed because we have the love of God shed abroad in our hearts by the Holy Spirit Who is given to us (Romans 5:2-5). Thus when they are chastened they should give thanks to our Father for the love and concern that He shows towards them.
Both James and Peter also stress the same lesson. James says, "You know that the testing of your faith develops patient endurance. And let patient endurance complete its work so that you may be mature and perfect, not lacking in anything" (James 1:3-4). While Peter adds, "These [trials] have come so that your faith -- of greater worth than gold, which perishes even though refined by fire -- may be proved genuine and may result in praise, glory and honour when Jesus Christ is revealed" (1 Peter 1:7).
The chastening described here is probably to be seen as that arising because they serve Christ. Everyone in the world at times face afflictions and distress. That is the common lot of men. They are more often seen as God's judgments rather than His chastening, although those too often have the purpose of awakening men to their sins. But when we suffer for Christ's sake, then we can see it as chastening, for it is special to His people.