Our Lord Jesus taught the Kingdom of Heaven, but just as he had friends, his disciples, he also had enemies, the Pharisees and the doctors of the Law. The Kingdom of Heaven is a deeply ethical doctrine, which reveals the new promises of God, not made to the children of Abraham according to the flesh, Israel, but to the children according to the spirit, that is, to the followers of the faith in our lord that also live in the spiritual gift of fear of God (constancy, firmness, devotion, equanimity, stability): "I now realize how true it is that God does not show favoritism but accepts from every nation the one who fears him and does what is right" Acts 10:34-35.
That is why Jesus warns to his listeners with a famous parable, the Parable of the Tenants (Matthew 21:33-45), that the blessings of God and his Kingdom will be taken away from those who do not accept his word and reject the spiritual salvation: "Therefore I tell you that the kingdom of God will be taken away from you and given to a people who will produce its fruit" Matthew 21:43. The word of our Lord is absolutely necessary to know God and his mysteries: "Blessed rather are those who hear the word of God and obey it" Luke 11:28.
Our Lord Jesus in this parable makes an interesting comparison, the vineyard is the world, and the people are the vineyard workers, the prophets and Jesus are the servants that God sends to verify the harvest; and God as the owner of the vineyard sooner or later is going to make the workers answer for how they have acted. Jesus teaches us with this that we must live attentively, to take care of our thoughts and our actions, to know how to interpret the signs of the times, because the owner of the vineyard will arrive at the least expected moment: "Therefore, when the owner of the vineyard comes, what will he do to those tenants?" Matthew 21:40.