When the Spirit of the Lord dwells within man that is Christ' coming through HIS Spirit. That's why before leaving this world Christ tells us He would come again soon, and that He is near. This is not Christ coming again in human form, but it is nonetheless Him coming to us, showing us that through His Spirit in us we can be with Him in heaven, where He is! Heaven, the spiritual habitation of God, no man could go without Christ being in us through His Spirit. And when His Spirit came to each believer as we are born again, we obtained entrance into heaven so that we could be with Christ forever. Believers don't have to wait for Christ to come the second time to be with Him and He to be with us. He is with us always through His Spirit unto the end of the world.
John 14:18 (KJV) I will not leave you comfortless: I will come to you.
John 14:2-4 (KJV) In my Father's house are many mansions: if it were not so, I would have told you. I go to prepare a place for you. And if I go and prepare a place for you, I will come again, and receive you unto myself; that where I am, there ye may be also. And whither I go ye know, and the way ye know.
Matthew 18:20 (KJV) For where two or three are gathered together in my name, there am I in the midst of them.
Matthew 28:20 (KJV) Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.
We're fixated on this physical/material world, but the Kingdom of God that is within every believer is not spiritually bound in this world. Through His Spirit in us, we have both KNOWN and ENTERED the Kingdom of God that is now in heaven and within us through Christ's Spirit in us. We cannot be with Christ physically until He comes again to make all things new, but we are spiritually with Christ through His Spirit in us forever, SPIRITS of men made perfect being justified according to grace through faith, and nothing, not even being in a body of flesh can separate us from Him.
Hebrews 12:22-23 (KJV) But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels, To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect,
Just as Christ ascended to the heavenly realm above, so too, we who have been born again of His Spirit have been made spiritually alive and raised up spiritually together with Him in the realm of God.
Ephesians 1:19-20 (KJV) And what is the exceeding greatness of his power to us-ward who believe, according to the working of his mighty power, Which he wrought in Christ, when he raised him from the dead, and set him at his own right hand in the heavenly places,
Ephesians 2:5-6 (KJV) Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved;) And hath raised us up together, and made us sit together in heavenly places in Christ Jesus:
Romans 8:33-39 (KJV) Who shall lay any thing to the charge of God's elect? It is God that justifieth. Who is he that condemneth? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us. Who shall separate us from the love of Christ? shall tribulation, or distress, or persecution, or famine, or nakedness, or peril, or sword? As it is written, For thy sake we are killed all the day long; we are accounted as sheep for the slaughter. Nay, in all these things we are more than conquerors through him that loved us. For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come, Nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord.