In Jews' mind of kingdom, they want their Messiah to take over Roman Empire and rule over the world as Jerusalem as world's capitol. In their mind that they are expecting Messiah shall set the kingdom upn earth as literal physical and political rule.
Jesus told them, it is not come with observation, it is within them, it is speak of spiritual come from heaven.
Premills believe Christ shall bring the kingdom to Jerusaslem, and will set it as world's capitol for a thousand years.
But, Christ already bring kingdom to the world 2000 years ago. Itself is a good news talk about Jesus Christ, calvary, resurrection, salvation, and reign.
Christ already given the kingdom to the Church by the Holy Spirit on Pentacost Day of Acts chapter 2. Itself is a gospel that the Church received the power from Christ - Matt. 16:18-19.
Premill believes kingdom will be presence to the world from Jerusalem in physical for 1000 years.
But, Dan. 7:14,18, and 27 telling us, the saints(Christians) already receive the kingdom of God and they already possess it, it is an everlasting kingdom, not temporary, so called, "millennial kingdom", as premills named it.
We have to accept the fact what Christ said to the Pharisees that, itself not come with observation, it is come within us from above is spiritual and eternality kingdom. It is mystery, but we have faith what the Bible saying. We as Christians already received the power given by Holy Spirit to preach the gospel to the world of what? Kingdom. Kingdom is all about Jesus Christ.
Notice two words of 'kingdom' - King + dom. dom is short word for 'dominion' means sovereign or reign.
Christ already sit on the right hand of God the Father in heaven since his resurrection, Christ is already exalted by God the Father to made Him a King over heaven and earth 2000 yeasr ago. We do not need wait for Jesus to 'become' King. He is now already King. We have the right to worshipping Christ, because He is our King. He is now reigning both heaven and earth from his throne.
When He shall come again, his reign never stop, He will continue reigning forever and ever without end. Kingdom have no end, it is everlasting.
That what the kingdom is all about.
In Christ
Rev. 22:20 -Amen!