Jesus spoke to the Jewish multitudes in parables because they were not supposed to understand the mysteries of the kingdom of heaven.
10 “And the disciples came, and said unto him, Why speakest thou unto them in parables?”
11 “He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given.”
12 “For whosoever hath, to him shall be given, and he shall have more abundance: but whosoever hath not, from him shall be taken away even that he hath.”
13 “Therefore speak I to them in parables: because they seeing see not; and hearing they hear not, neither do they understand.”
14 “And in them is fulfilled the prophecy of Esaias, which saith, By hearing ye shall hear, and shall not understand; and seeing ye shall see, and shall not perceive:”
15 “For this people’s heart is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes and hear with their ears, and should understand with their heart, and should be converted, and I should heal them.”
16 “But blessed are your eyes, for they see: and your ears, for they hear.”
11 “And he said unto them, Unto you it is given to know the mystery of the kingdom of God: but unto them that are without, all these things are done in parables:”
12 “That seeing they may see, and not perceive; and hearing they may hear, and not understand; lest at any time they should be converted, and their sins should be forgiven them.”
9 “And his disciples asked him, saying, What might this parable be?”
10 “And he said, Unto you it is given to know the mysteries of the kingdom of God: but to others in parables; that seeing they might not see, and hearing they might not understand.”
John 9:39: “And Jesus said, For judgment I am come into this world, that they which see not might see; and that they which see might be made blind.”
Jesus’ plan was to save all mankind, not just the Jews. In order for salvation to go to the Gentiles the Jews had to reject Him and then salvation could go to the rest of mankind.
Mark 8:31: “And he began to teach them, that the Son of man must suffer many things, and be rejected of the elders, and of the chief priests, and scribes, and be killed, and after three days rise again.”
Luke 9:22: “Saying, The Son of man must suffer many things, and be rejected of the elders and chief priests and scribes, and be slain, and be raised the third day.”
John 1:11: “He came unto his own, and his own received him not.”
Jesus came unto his own and they received Him not. This is because He spoke to them in parables, and they did not understand the mysteries of the kingdom. If the Jews had understood the teachings of Jesus and repented, then they would be saved. If this had happened only the Jews would have access to eternal life.