The most transparent words in the Gospel, and the essence of the good news.
And someone asked him, “When will the kingdom of God come?”
And he said, “The kingdom of God will not come if you watch for it. Nor will anyone be able to say, ‘It is here’ or ‘It is there.’ For the kingdom of God is within you.”
someone asked him: Luke reads, “The Pharisees asked him.”
The Pharisees as auditors have been introduced by Luke, who found the saying with no hearers mentioned, just as in certain cases he seems to have constructed the situation from the saying itself. The saying might suggest “disciples” or “the people” or “a certain man,” but “Pharisees” seems hardly possible.
(Burton Scott Easton, “Luke 17:20-21. An Exegetical Study,” American Journal of Theology 16,p. 279)
When will the kingdom of God come: My friend the Zen teacher John Tarrant comments, “Ordinary mind is the Tao. If you turn toward it, you turn away from it.”
if you watch for it: Literally, “with observation,” that is, “with outward signs that can be perceived.”
My experience tells me that the Kingdom of God is within us, and that we can realize it not by saying “Lord, Lord,” but by doing His will and His work. If, therefore, we wait for the Kingdom to come as something coming from outside, we shall be sadly mistaken.
(Mohandas K. Gandhi, The Collected Works of Mahatma Gandhi, vol. 37, The Publications Division, Ministry of Information and Broadcasting, Government of India, 1970, p.261)
There is an important passage from the Gospel of Thomas that helps to explain the present saying:
Jesus said, “If your teachers say to you, ‘Look, the kingdom is in heaven,’ then the birds will get there before you. But the kingdom is within you, and it is outside you. If you know yourselves, then you will be known; and you will know that you are the sons of the living Father.” (Thomas, 3)
within: The Greek preposition entos is, in many modern versions, translated “among.” But its regular meaning is “within”; it is used in Matthew 23:26 to mean “the inside” (of a cup); and in the Septuagint, which Luke knew well, it always refers to the inward parts of a person (“my heart within me,” Psalms 39:4 and 109:22; “everything within me,” Psalm 103:1).
(i) entos is properly a strengthened form of en used where it is important to exclude any of the possible meanings of that preposition other than “inside.” …(ii) When Luke means “among,” he says en mesoi, an expression which occurs about a dozen times in the Third Gospel and the Acts. If he meant “among” here, why did he vary his usage? (iii) If appeal be made to an underlying Aramaic, the prepositions in that language meaning respectively “among” and “within” are distinct, and there is no reason why a competent translator should confuse them. (iv)“Among” does not give a logical sense. A thing which is “among you” is localized in space, more or less. On the other hand you cannot say “Lo here, or there!” of that which is “within,” and the Kingdom of God is said not to be localized in space, because it is entos humōn. This might be understood as the counterpart of the “Q” saying discussed above: the Day of the Son of Man is not localized in space (or time) because it is instantaneous and ubiquitous; the Kingdom of God is not localized because it is “within you.” In other words, the ultimate reality, though it is revealed in history, essentially belongs to the spiritual order, where the categories of space and time are not applicable. There is however another possible meaning. In the Harvard Theological Review, vol. xli, no.1 (1948), C.H. Roberts argued persuasively on the basis of evidence from papyri and elsewhere, that entos humōn means “in your hands,” “within your power.” That is, the Kingdom of God is not something for which you have to watch anxiously (ou meta paratērēseōs), but is an available possibility here and now, for those who are willing to “receive it as a little child.”
(C.H. Dodd, The Parables of the Kingdom, Charles Scribner’s Sons, 1961, pp. 62f.)
For the kingdom of God is within you: Where is this “within”? It can’t be observed by a surgeon, just as heaven can’t be found by an astronaut.
Ramana Maharshi comments:
The ultimate truth is so simple. It is nothing more than being in the pristine state. This is all that needs to be said.
All religions have come into existence because people want something elaborate and attractive and puzzling. Each religion is complex, and each sect in each religion has its adherents and antagonists. For example, an ordinary Christian won’t be satisfied unless he is told that God is somewhere in the far-off heavens, not to be reached by us unaided; Christ alone knew Him and Christ alone can guide us; worship Christ and be saved. If he is told the simple truth, that “the kingdom of heaven is within you,” he is not satisfied, and will read complex and far-fetched meanings into it.
Only mature minds can grasp the simple truth in all its nakedness.
source: Luke 17:20f.