can sometimes be heard and/or felt. Scents, tastes, sounds. Wind, friction, gravity. Ambient temperature. Energy. Emotion. We see the effects of these things, but we do not see these things. We know they are real because all human beings experience their effects in consistent ways.
Now, God's Spirit is also unseen. But how is it felt? Superstition has always worried me more than confidence here, even to my own detriment. But lots of people have claimed to feel things that I didn't believe they were feeling, and lots of people have found it convenient to report hearing God when the message was kind to their whims. I could hear from Santa Claus if I tried hard enough. But what's real? What's true? In other words, what should I believe? And what can I feel?
Faith is being convinced about things we cannot see. This includes staying confident about what we did actually feel. What we think we remember feeling. What we might feel again.
Yet, we doubt, often, because all human beings do not report the same type of spiritual experience. In the end, that is partly because lots of us are confused, and partly because too many lie. But it may also be God's way of keeping us on our toes.
Still, we should never discount the power and necessity, for all of our christian lives, of experiencing God's spiritual reality. Faith is believing in things unseen. Not unfelt.