The Holy Spirit is like the indentation from a wedding band on your ring finger. You may try to pretend that you aren't married, or you may even take off your ring in hopes of deceiving someone else or yourself. But that smooth white band of shiny skin on your finger is the tell-tale sign that a ring has been worn on that finger for quite some time.
The Holy Spirit is like that smooth indentation under your wedding ring. If you truly know Christ, then a part of God Almighty lives inside you, as the Lord's signet ring, sealing you to Him for all eternity. No one can fake that confident sense of "belonging" to Christ, just like no one can fake that ring indentation. And no one can remove the indentation, not without removing the wedding band and exposing the area to lots of sunlight for an extended period of time. Just like no one can remove the Holy Spirit from you, once you have Him. He is yours; you are His.
You may not want to "feel" like you're married, just like there are surely some days when you may not "feel" like a Christian. But the Holy Spirit is always there, that smooth little band around your heart, ensuring that you belong to Him, forever.
The point of all this is as follows: even if you remove that gold wedding band, which is the outward symbol of love, devotion, and belonging to someone, that small white line still remains beneath it, encircling your finger like a scar, showing the world that a grand display of commitment used to reside on that finger. The effects and sentiment remain wrapped around your finger, even if the outward symbol is removed.
Now, I realize that this is an imperfect analogy, because after you remove a wedding band, the little white smooth band will fade over time; the proof of your prior commitment slowly fading into oblivion. But it would take awhile, and it may never truly fade completely. Would that area of skin ever truly be the same again, as it was before you placed that ring on your finger? I don't know and I don't plan on finding out.
But the point remains the same: the Holy Spirit, once accepted into your heart, remains for always, encircling your heart, even if you allow Him to fade a bit. You may remove that outward symbol and turn away from Christ, but He will never turn away from you. He is like the most faithful, committed, loving Husband who fights for you and longs for you to know Him completely.
"You, however, are not in the realm of the flesh but are in the realm of the Spirit, if indeed the Spirit of God lives in you. And if anyone does not have the Spirit of Christ, they do not belong to Christ."