Lk 17:20 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.

Man is basically good, but he is also a brute. The change from from good to "brutish" actually happens in every single child. God is, therefore, inside man, and not to be sought for outside alone. The Kingdom of Heaven is the Kingdom of the inner grace and goodness, and not the mystical "beyond" with angels and devils into which the brute in the human animal has turned its lost paradise.

When we reach the end of what we know, that's where we find God.