Human beings are born with a body and soul. Once born from above, we gain a living spirit and that spirit becomes one with the living Spirit of God. All three can sense. My body has five senses through which I experience the physical world. My soul has a mind, will and emotions through which I experience my self. My spirit has the ability to sense God.
It's beside the point to debate whether the spirit is or becomes part of the soul. It also does not matter whether babies are born without spirit or with a dead spirit ('inherited from Adam & Eve') that becomes alive when one is "born of God". What matters is that a pagan can pray to a stone idol, pretend to hear instructions from it, and imagine its pleasure or displeasure. But a christian can do more.
The indwelling of the Holy Spirit is not metaphorical. It is metaphysical. And "spirit" is every bit as real as concrete. Yes, there is a way in which faith always remains blind but true christianity is about spiritual experience, as frightening as that may be. Faith is necessary because it takes courage to believe what your spirit is telling you and confidence to keep believing what you've sensed when the sensation isn't so present.
If you suddenly grew a second set of arms they'd have to be strengthened, but at least you'd already know how to use arms. How does one grow accustomed to the proper use of a spirit when one has been living by mind, will and emotions for so long? It doesn't help, either, when one is trained to use ones soul, primarily, in pursuit of the spiritual.
Mainline theologians usually treat this distinction as if it were minor and mostly academic, which makes sense because Institutional Christendom does not like to promote what it cannot control. If ecclesiastical authorities taught that the headship of Christ were direct over every believer, functionally, they'd have a harder time denying the functional priesthood of ever believer.
Regular readers know I don't get into theology. But I don't consider this theology. I consider this biology.
Your spirit is as real as your lungs, and as different from your soul as the lungs are from the heart. The soul is the seat of the spirit like the heart pumps oxygen through the blood, but the blood is not oxygen and the blood cannot provide life to the body without air first filling the lungs.
In the same way, the human soul is a beautiful part of how God intends men and women to direct themselves in the physical world, but the soul must learn how to be in subjection to the spirit. Otherwise, christians are just pagans pretending to be spiritual.
By the way, I know this to be true both by experience and from the scriptures. But I won't try to prove it from either. First, you can argue anything by quoting scripture. Second, if you don't actually work this out experientially, it doesn't matter whether you 'believe' it.
Why does this matter? Because a great many christians treat the reality of a christian's intimacy with God as if it were largely make-believe. Faith is not about believing something that seems unreasonable. Faith is being confident in that which you know, even when 90% of everyone else in your city thinks you're insane. "Belief" comes when you accept an argument, choose to overlook its flaws, and/or enjoy the conditions of having been persuaded. "Confidence" comes only from knowledge and experience.
Faith is being confident in that which we cannot see. Spirit is invisible.