Scientists and ...!, page-1171

Kam, the apostles were not yet able to accept what they needed to learn.That the disciples had much to learn is evident from their question to Jesus after his resurrection. They asked him: “Lord, are you restoring the kingdom to Israel at this time?” (Acts 1:6) It was not until later that they fully realized there was not to be a fleshly kingdom in which they would participate. The Kingdom was to be a heavenly arrangement. We can appreciate Jehovah’s loving-kindness in giving the disciples these truths gradually, since the belief of a literal king’s coming to throw off the Roman yoke and set up an earthly kingdom was a deep-seated hope of the Jews at that time. Had this truth of the Kingdom’s being in heaven and not on earth been revealed at the time Jesus first called out his disciples, they might not have had the maturity to understand, appreciate, and continue following him.
   This was the case with many of Jesus' disciples. After he had fed thousands starting with just of few loaves and fishes the crowds correctly concluded:“This really is the Prophet who was to come into the world.” (John 6:14)
What they wanted from Jesus is made evident by the next verse.
(John 6:15) Then Jesus, knowing that they were about to come and seize him to make him king, withdrew again to the mountain all alone.
But what was their reaction when he refused to be made king? 
(John 6:66) Because of this, many of his disciples went off to the things behind and would no longer walk with him.
    Read the whole ch 6 and you will see there was a danger in trying to adjust their thinking too much too soon.

Jesus' attempts to instruct the whole crowd proved futile. He focused instead on his closest disciples.
(John 6:67, 68) So Jesus said to the Twelve: “You do not want to go also, do you?” 68 Simon Peter answered him: “Lord, whom shall we go away to? You have sayings of everlasting life.
  Jesus well understood the principle contained in the proverb:'' Like apples of gold in silver carvings Is a word spoken at the right time'' (25:11).