The most frequent references to the Kingdom of Heaven or Kingdom of God occur in the Gospel According to Saint Luke. It is in this gospel that Jesus speaks of the coming of the Kingdom, (chapter 17 verses 20-37). Jesus also taught his disciples:

"Let the little children come to me, and do not hinder them, for the Kingdom of God belongs to such as these. I tell you the truth, anyone who will not receive the kingdom of God like a little child will never enter it." Luke chapter 18 verses 16-17

Also in Luke Jesus states, "How hard it is for the rich to enter the Kingdom of God! Indeed, it is easier for a camel to go through the eye of a needle than for a rich man to enter the Kingom of God." (chapter 18 verses 24-25)

Luke relates that at the Last Supper, Jesus said, "I tell you I shall not drink of the fruit of the vine until the Kingdom of God comes." Luke chapter 22 verse 18

In the gospel of John Jesus states a fundamental tenet of Christianity concerning the Kingdom of God. "I tell you the truth, no-one can see the Kingdom of God unless he is born again." John 3 verse 3