Having seen how Jesus fed 5,000 families and then 4,000 families on different occasions, we might think that the disciples would not have any concern about the next meal. Either that or they would always ensure they had sufficient food supplies. So it seems strange to read that they set out on another journey without food because they forgot.
The disciples had left the bread behind; so when Jesus talked about the 'yeast of the Pharisees and Sadducees' they thought He was criticising their failure. They really wanted to please the Lord. However His holiness was a continual reminder of their sinfulness, giving them an inner urge to do better but also the sinking realisation that they could not meet His standard.
A person's true identity is very important. Many pretend that they are something they are not; and some prefer not to be recognised for who they are or what they have achieved. But understanding who you are talking to is essential for real relationship. The trainee apostles had spent over a year with Jesus; they observed the integrity of His character, heard the wisdom of His teaching, saw His compassion and power expressed in many miracles, and had been rebuked for failing to trust Him.
Simon Peter had just confessed that he believed that Jesus was the Christ, the Son of the living God. It was a huge statement and maybe even surprised the brazen fisherman. But Jesus quickly stepped in to remove any sense of pride from Peter; and then to set before the trainee apostles a mission which was impossible – except for God.
Peter had just declared that Jesus was the Christ (Messiah), the Son of the living God. It was God's direct revelation to him, and Jesus declared that such faith would become the foundation of the church. Peter would have felt that he was certainly 'on-side' with Jesus. It was the 'high point' of the disciples' interaction with Jesus: they were now confident they knew who He was. But, at the same time, the countdown to the cross had begun.
The disciples of Jesus were naturally sinful and selfish – like the writer and readers of Word@Work. Their instincts were to advance themselves and use anyone else including Jesus to do so. Although they were on a training course to be the apostolic leaders of the church, they were more concerned with their own welfare. So when Jesus told them that He would suffer at the hands of the religious leaders and be killed, they could not accept it: surely, they thought, Jesus would become the popular king of Israel and they would share His glory.
For us human beings, death appears to be the end. That is what the disciples thought when Jesus told them He would die at the hands of violent religious men. But after the cross comes the crown. That's a certainty because Jesus is the eternal King. It was impossible for the disciples to visualise what Jesus meant in these verses, but they held the words (we know because they were written down) until they could understand.
Six days previously, Jesus told the disciples that some of them would not die until they had seen Him in His glory (Matthew 16:28). So soon was the promise fulfilled. He took the three men who would become the leading apostles to show them something of His supernatural nature. Why just three? They were to be eye witnesses who all saw and heard the events on that mountain; and were confident to give that evidence to the Early Church.
This was a unique occasion. Jesus was physically changed; His face and clothing were brilliantly white (Matthew 17:2). Father God validated Jesus as His Son. Moses and Elijah were there too, recognisable and talking with Jesus (Matthew 17:3). It was a foretaste of heaven in which Jesus affirmed the previous ministry of the Law and the Prophets.
If the glorious appearance of Jesus with Moses and Elijah startled Peter, James and John - the audible voice of God terrified them. "While he was still speaking, a bright cloud covered them, and a voice from the cloud said, 'This is my Son, whom I love; with him I am well pleased. Listen to him!'" (Matthew 17:5).