In the second post we explored the heart of that contrast. Specifically, psyche/soul is closely associated with natural, animal, biological life. "Soulish life" is animal life. Pneuma, by contrast, is properly "spiritual," something wholly other from animal life.
Understanding these associations, how soul is more "animal" than "spiritual," helps us understand the contrasts between psyche and pneuma in some New Testament passages in 1 Corinthians.
Consider 1 Corinthians 2.14-15. Here is the translation in the ESV, selected because the ESV is trying to be a "literal" word-for-word translation of the Greek text:
The natural person does not accept the things of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned. The spiritual person judges all things, but is himself to be judged by no one.
Reading this "literal" translation from the ESV you wouldn't know that the word psyche is in play. Nowhere do you see the word "soul." And yet, crucially for this series, psyche is present in the text, and it's the word "natural"! Do you see, here, the point I made in the last post? For Paul, our word "soul" is more akin to "natural" than to "spiritual," as this passage makes abundantly clear. To make the Greek text more transparent, here's David Bentley Hart's translation of the passage above:
But a Psychical man does not receive the things of God's Spirit; for to him it is folly, and he is unable to know them, since they are discerned spiritually. The Spiritual man, moreover, discerns all things, yet it is discerned by no one.
But even Hart's translation isn't making it as clear as I'd like it to be for us. So, taking a cue from Hart and revisiting the ESV translation above, here's the contrast between psyche and pneuma in 1 Corinthians 2.14-15:
The psychical, soulish person does not accept the things of the Pneuma of God, for they are folly to him, and he is not able to understand them because they are pneumatically discerned. The pneumatical person judges all things, but is himself to be judged by no one.
Here's the point. In almost every English translation you wouldn't know that the word translated as "natural" in this text is psyche, the word for "soul." English readers of the Bible have never encountered the vey close association between natural, biological life with the word "soul." Again, the New Testament word for "soul" is closer to animal life than to spiritual life. Which is precisely Paul's point above. A merely natural, biological person cannot discern pneumatical truths. For pneumatical truths can only be discerned pneumatically. They can't be discerned psychically, naturally, or soulishly.
A merely soulish, psychical, natural person cannot discern the Pneuma of God and the Pneumatical Life.
