If you are going to introduce "Heaven is coming to Earth" as a fact having scriptural support, then the onus is on you to be specific since Revelation chapters 21 and 22 contain 27 and 21 verses in them, respectively and while Revelation 20:2 does make reference to "holy city, New Jerusalem, coming down out of heaven from God" and Revelation 20:10 does make reference to "the holy city Jerusalem coming down out of heaven from God," there nothing at all contained in these 48 verses about "Heaven is coming to Earth."
Wow, djegg. That shows a very clear Watchtower perspective and how they don't understand hermeneutics or exposition. Christians don't need to rely on "proof texts" like you and other JWs do. If you read ALL of Revelation (and especially 21,22) you will see that the end result of God's Kingdom is that He will LIVE among mankind. As the NWT says, "He will reside with them."
The New Jerusalem is the city of Heaven. It is Heaven itself. Jerusalem was where God's throne was located. So if you say that New Jerusalem is coming down out of Heaven and God will reside with men, then you have your answer.
What Syl said was EXACTLY correct.