Jesus presents the Kingdom of God to us as a mysterious doctrine, not all who listen to Jesus can understand with their hearts. The truth is that living the spiritual gifts is not like practicing the moral virtue, spirituality begins with the fear of God (constancy, firmness, devotion, equanimity, stability), and without this spiritual gift, all knowledge about Jesus is useless. Jesus is clear, we have to choose between the love of God and the love of money, we enter into the Kingdom of God by a grace, a charism.
And with Jesus, this Kingdom of Heaven announced by the prophets reaches its fulfillment: "Because the kingdom of God is in your midst" Luke 17:21. That is why our Lord Jesus, filled with the Holy Spirit, explains that the knowledge of the Kingdom of God, the dominion of God's perfections, was reserved for his arrival, that he as Messiah and Son of Man, was in charge of revealing the divine mysteries to us.
Jesus explains to us that he is the way to that perfect wisdom of the Father and the Holy Spirit, of that wisdom that is not for the proud but for those who become children again, that wisdom that makes us similar to God, as he explains in the Gospel of Luke:
"At that time Jesus, full of joy through the Holy Spirit, said, ´I praise you, Father, Lord of heaven and earth, because you have hidden these things from the wise and learned, and revealed them to little children. Yes, Father, for this is what you were pleased to do. ´All things have been committed to me by my Father. No one knows who the Son is except the Father, and no one knows who the Father is except the Son and those to whom the Son chooses to reveal him.´ Then he turned to his disciples and said privately, ´Blessed are the eyes that see what you see. For I tell you that many prophets and kings wanted to see what you see but did not see it, and to hear what you hear but did not hear it´" Luke 10:21-24.