20 And when he was demanded of the Pharisees, when the kingdom of God should come, he answered them and said, “The kingdom of God cometh not with observation: Neither shall they say, ‘Lo here! or, lo there!’ for, behold, the kingdom of God is within you.”
This means that the “kingdom of God” (heaven) is within – it is not a place to be reached, rather a state to be experienced.
One can call the “kingdom of God” (heaven) whatever one pleases – Zen, enlightenment, etc. This wisdom crosses all boundaries and unites all as one – “beings.”
(Thank you “xinyuan” for the quote)