Continuing though a section of the Gospels which is uniquely in Luke, we have come to two little verses which wrinkle the traditional Christian eschatology. Prior to these verses, Jesus explained how you should consider yourself a worthless slave of God, and then later He healed ten lepers, but only the Samaritan leper came back to thank Him.
The Kingdom Within You
Kingdom of God given by Jesus. In general, they fell into one of two categories: one, a growing spiritual constituency, and the other, a reference to an eternal Kingdom physically on earth soon to be established. The implication being that the spiritual constituency would be the residents of the Kingdom to come.
You may be wondering if God's Kingdom is going to be established, then when is that supposed to happen? According to Luke 17:20-21, you are not the only one:
Once, having been asked by the Pharisees when the Kingdom of God would come, Jesus replied, "The Kingdom of God does not come with your careful observation, nor will people say, 'Here it is,' or 'There it is,' because the Kingdom of God is within you." NIVAs I had mentioned in the original discussion about the Kingdom of God, the Pharisees asked when the Kingdom would come. Or, given that they fully expected what the Scripture had actually prophesied, a better way to render their question may be "when will God establish His literal, earthly Kingdom?" There was no question of where that Kingdom would be, because the Scriptures, such as Zechariah 1:16-17, explicitly indicate that it would be in Israel, centered around Jerusalem.
According to Luke, Jesus does not really answer their question. Instead, He tries to correct their way of thinking. First, He says that the kingdom will not come with their observation, which may either be taken to mean that they will not be able to see it, or, in the other sense of observation, that their obeying of laws and rituals will not usher in the Kingdom. The former suggested meaning is more favorably aligned with the phrase that would follow: "the Kingdom of God is within you."
It should be noted that the word translated as "within" is "entos" in the Greek, which can also mean "among." In fact, some translations render the verse to the effect of "the Kingdom of God in your midst." Such an interpretation suggests that the Kingdom already existed in Jesus' time, perhaps meaning that the believers were collectively the Kingdom; a Kingdom without a country.
Also, what is likely obvious, note that the "you" is not indicating the Pharisees particularly, but rather a generalized pronoun which could be replaced functionally by the word "people."
What Luke is doing here is redefining Jewish eschatology. I say Luke, not Jesus, because this sentiment is unique to Luke. This is not a message about a growing constituency. This is a redefining of the concept of the Kingdom of God. Luke's/Jesus' words here imply that the literal, earthly Kingdom of God (in the sense of a traditional nation-kingdom) will never come to be, at least not in this life. Possibly more significant is the other possible implication; that the Kingdom of God already existed.
If we accept these possible interpretations of Luke's words here, they do not fit within the Gospels. This is evident in a couple ways. The first bit of evidence is a little weak because it is circumstantial. Namely; the eschatology-shattering impact of Luke's words were, for all practical purposes, ignored for well over a thousand years. It is hard to know exactly when they started to be ignored, but it was not until the 20th century when C. H. Dodd and John Dominic Crossan advanced the theory of "realized eschatology" that Luke's words here became truly relevant again. Realized eschatology, also known as "sapiential eschatology," states that the Kingdom did start with Jesus, who gave a rebirth to the world order through His teachings and life, and it thereby puts the responsibility on believers to imitate Jesus in order to make fully manifest the already initiated and existing Kingdom of God. That is a nice sounding story, but it is not at all consistent with the Old Testament prophecies.
The second piece of evidence comes right from Luke's Gospel itself. Luke was writing contemporaneously with an established belief in apocalyptic eschatology. This is captured in Matthew 24 and Mark 13, where you will find talk of the cataclysmic end times and Second Coming of Jesus. Matthew 25 continues on, making it obvious that it is during that event when the Kingdom of God will really be established, and when the final Judgement of mankind will be made. Luke 21:5-36 covers that same apocalyptic material, and it does so within the same part of the narrative as Matthew and Mark.
Obviously then, Luke agrees the apocalyptic eschatology. So what is the real truth with this Kingdom-within-you stuff? I am not certain, but I think an answer becomes apparent when we consider a little more context.
First, remember that Jesus was replying to the Pharisees with the Kingdom-within-you. You may remember in an earlier study, one regarding why Jesus spoke in parables, that the "secret of the Kingdom of God has been given" to the disciples, not to "those on the outside." So why would Jesus reveal such a monumental "truth" to the Pharisees? That does not make sense.
Right after this statement about the Kingdom of God being within you, Luke 17:22-37 has some of the same apocalyptic material which is also covered later in Luke 21:5-36, but it starts off a bit differently. In Luke 17:22 you see:
Then He said to His disciples, "The time is coming when you will long to see one of the days of the Son of Man, but you will not see it." NIV
Notice the "Then," connecting this passage with the previous one. Note that Jesus is speaking to His disciples here, not the Pharisees any more. It appears that Luke's Jesus is preparing His disciples for a long wait for His return.
Also, we have to consider that Luke most likely wrote his Gospel sometime after the destruction of the Temple in Jerusalem, and so believers and scoffing Jews alike would have been anxious about when the alleged Jesus-led version of the Kingdom of God would come to fruition.
When you piece this information together, it seems more likely to me that Luke's message here is how disciples can silence adversaries, and how they need to be patient in waiting for the Kingdom. So Luke has Jesus simply trying to brush-off the questioning Pharisees, trying to get them to stop asking "when" by replying with some mystical language about a Kingdom within you. Then Luke has Jesus speak to the disciples, the ones who really know the truth, urging them to be vigilantly patient.