The mind sciences and many “new age” type religions and beliefs use this Scripture to say that everyone has God within them. “The kingdom of God is within you,” is interpreted as all of God's power and truth are built into you.

The word “within in the Greek is “entos,” which is accurately translated “in the midst of”. So it really should be understood as Jesus saying the Kingdom of God is within your midst, or among you. In other words, wherever Jesus is, it accompanies him. What it does NOT mean is that it resides in everyone.

It does not mean inside man because of whom Jesus was addressing – the Pharisees. They rejected Jesus and his teachings.

Jesus told this same group of Pharisees that rejected him "You are of your father the devil, and the desires of your father you want to do” (John 8:44). [ not all the Pharisees disbelieved, a small portion of them believed Jesus].  Furthermore, Jesus taught one of the Pharisees specifically that to enter the kingdom he must be born again (John 3), to have a spiritual birth, even though he was the teacher to the people of Israel.

Luke 17:20-21 “Now when He was asked by the Pharisees when the kingdom of God would come, He answered them and said, "The kingdom of God does not come with observation;  nor will they say, 'See here!' or 'See there!' For indeed, the kingdom of God is within you.”

Jesus made it clear in response to their unbelief “But if I cast out demons by the Spirit of God, surely the kingdom of God has come upon you.” (Matt 12:28)

In other words it accompanied His person and was  made known to them.

Luke 18:25-26 “it is easier for a camel to go through the eye of a needle than for a rich man to enter the kingdom of God ." And those who heard it said, "Who then can be saved?"

So it is equated with salvation- found only in Jesus Christ.

Mark 12:29-34 we have a scribe asking Jesus, “Which is the first commandment of all?" Jesus answered him, "The first of all the commandments is: 'Hear, O Israel, the LORD our God, the LORD is one. 'And you shall love the LORD your God with all your heart, with all your soul, with all your mind, and with all your strength.' This is the first commandment. And the second, like it, is this: 'You shall love your neighbor as yourself.' There is no other commandment greater than these." So the scribe said to Him, "Well said, Teacher. You have spoken the truth, for there is one God, and there is no other but He. And to love Him with all the heart, with all the understanding, with all the soul, and with all the strength, and to love one's neighbor as oneself, is more than all the whole burnt offerings and sacrifices." Now when Jesus saw that he answered wisely, He said to him, "You are not far from the kingdom of God.”

The Scribe did not possess the kingdom within but needed to do what prevented him from following Jesus so he would enter the kingdom

Matt 21:31 “Assuredly, I say to you that tax collectors and harlots enter the kingdom of God before you.”

That would be difficult if the kingdom is already within everyone. He is speaking of them entering a literal kingdom that is in the future.

Matt 21:43-44: “Therefore I say to you, the kingdom of God will be taken from you and given to a nation bearing the fruits of it. ”

In other words it would be taken from the people who denied him as a nation and given to other people.

At the last supper before his crucifixion Jesus said, “Assuredly, I say to you, I will no longer drink of the fruit of the vine until that day when I drink it new in the kingdom of God” ( Mark 14:24-25). This makes it clear that the kingdom is not on earth yet.

In Luke 9:27- “ But I tell you truly, there are some standing here who shall not taste death till they see the kingdom of God ." About eight days after He took Peter, John, and James and went up on the mountain and they saw Jesus transfigured into His glory He hid within Himself, and along with the appearance of Moses and Elijah that would be present when Jesus establishes his kingdom on earth. They were able to get a glimpse into the future kingdom that would be for the saints.

Other Scriptures on the Kingdom of God that explain it no being within all people.

Luke 19:11: “they thought the kingdom of God would appear immediately”

Luke 21:31: “when you see these things happening, know that the kingdom of God is near”