Question #3: What are the "things of the Spirit"?

Those who are in the flesh set their minds on the things of the flesh, but those who are in the Spirit, the things of the Spirit.

This is stated like a natural law, almost. But what are those "things of the Spirit" to which we should (or, if you read it like that, DO) set our minds? Here's what Matthew Henry has to say about it, in his commentary on Romans 8:

"The favour of God, the welfare of the soul, the concerns of eternity, are the things of the Spirit, which those that are after the Spirit do mind. Which way do our thoughts move with most pleasure? Which way go our plans and contrivances? Are we most wise for the world, or for our souls?"

More on this later.