Christ defined it since He is the only King of kings and Lord of lords, and He has granted to His dsciples the correct understanding.
And the disciples came and said to Him, "Why do You speak to them in parables?" He answered and said to them, "Because it has been given to you to know the mysteries of the kingdom of heaven, but to them it has not been given. For whoever has, to him more will be given, and he will have abundance; but whoever does not have, even what he has will be taken away from him. Therefore I speak to them in parables, because seeing they do not see, and hearing they do not hear, nor do they understand. And in them the prophecy of Isaiah is fulfilled, which says: 'Hearing you will hear and shall not understand, And seeing you will see and not perceive; For the hearts of this people have grown dull. Their ears are hard of hearing, And their eyes they have closed, Lest they should see with their eyes and hear with their ears, Lest they should understand with their hearts and turn, So that I should heal them.' "But blessed are your eyes for they see, and your ears for they hear; for assuredly, I say to you that many prophets and righteous men desired to see what you see, and did not see it, and to hear what you hear, and did not hear it. (Matthew 13:10-17)"For Jews request a sign, and Greeks seek after wisdom; but we preach Christ crucified, to the Jews a stumbling block and to the Greeks foolishness, but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God." (1 Cor. 1:22-24)
It would be more convincing if you'd actually use inspired writings.