The Biblical evidence is more nuanced than your formulation, Jesusfan. If we accept that the Bible is a closed book, a view I accept, then there are no more people speaking God's word for others to accept. No one can turn to the last page of the Bible and start writing new scripture. So, like many others, I am what is termed a cessationalist, there are no longer apostles and prophets, that foundation has been laid and there is no need to lay another foundation.
But that does not preclude God's Spirit from enlightening us, by helping us understand the message of scripture. Scripture says that without the aid of the indwelt Spirit, we cannot understand some spiritual things, the solid food spiritual things, but only the milk. So either no one is maturing, or God is providing insight in a way other than a fallen man gets by reading the text.
P.S. I see I left one point out, (1) God speaks to us through the Bible, and so if a "commentator" enlightens us with stuff that does not fit with the Bible, that "spirit" is not of God.
Now as for "how" our Holy Spirit provides that insight, I see nothing to limit the revelatory grace to "aha" moments during eyes closed prayer, so we might wake up with an idea or feeling of peace over something that was on our mind when we went to sleep. My Dad told me of a "dream" he had during a "near death" moment where he was walking near a stream. For the last year of his life, he was at peace with the world, knowing (at least in his mind) that the gates of heaven were standing open to him. Praise God.