The twelve disciples were the trainee apostles (Luke 6:13).  In such a short time, Jesus called the men He had chosen, and He then exposed them to a wide variety of ministry situations … including many sessions of teaching through parables, and afterwards explaining them (Matthew 13:10-17).  All this training was to equip them for the time when, in Jesus’ absence, they would lead the fledgling church under the direction of the Holy Spirit (John 16:12-16).  Jesus’ tuition would shortly come to an end: violently, by cruel execution on a Roman cross.  The disciples needed to know it was all part of the salvation plan (1 Peter 2:22-24).
 
While most of Jesus' teaching intrigued the disciples so that they would ask further questions, Jesus had already specifically twice told them about His death (Matthew 16:21, Matthew 17:22-23).  This was the third time.  It was not a riddle to stimulate them; nor a response to any known question.  Jesus deliberately stopped by the roadside and said to the twelve men, ‘I have something important to tell you, you must listen’.  We know what He was talking about, but the disciples still could not grasp something so shocking (Luke 18:31).
 
Nevertheless, Jesus told them exactly what would happen to Him.  Indeed, the Lord had orchestrated every part of the terrible suffering so that it would be a just punishment for the sins of the whole world (1 John 4:10).  His subsequent resurrection was also a part of the big gospel plan (2 Corinthians 5:15).  If Christ had not risen there would be no hope for the church.  However, His resurrection gave proof that He was stronger than death.  It would inspire many millions of people to believe in the living Lord Jesus Christ, as the only life-giving death-conquering Saviour (1 Corinthians 15:20-23), who promised to raise to eternal life all who die in faith (John 6:40).  What an example to those men, most of whom would be martyred for their faith that reached beyond the grave.  
 
Unlike human society, in which power comes through military or political conquest, the kingdom of God depends upon the suffering of its Leader.  We can never suffer like Jesus, for the sins of the world, but we are often called to share in His sufferings … as the world continues to hate Him and His people (Romans 8:17).  Many who come to Jesus for all the 'added benefits', may also go away when life becomes hard.  A gospel that is all blessing and no suffering is flawed.  If you are suffering for Christ's sake, your faith is not defective; you have not believed a lie.  Suffering is all part of the package which comes with Jesus (Philippians 1:29; Philippians 3:10).  When it comes - do not treat it with disdain; bear it as a privilege, with intentional courage, as Jesus and the apostles chose to do (Matthew 5:11-12).