1 Corinthians 2:14
1 Corinthians 2:1414The natural man does not accept the things that come from the Spirit of God. For they are foolishness to him, and he cannot understand them, because they are spiritually discerned.
JW evangelism presupposes that an unregenerate person can, given enough literature and enough time, research their way to recognising the truth. "You would not buy a car without researching it." The seeker weighs the publications against the Bible, decides they are accurate, and submits to baptism — all by the lights of his own reason. Paul's "natural man" is typically read as someone who has refused to engage, not as someone whose unregenerate state prevents spiritual discernment in the first place. Where the verse is cited at all, it is usually narrowed to "deep spiritual mysteries" as distinct from the basic gospel, allowing the publisher-training pathway to stand.
Read the verse slowly with the Witness. Paul says the natural man "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 whole JW evangelistic method — read, weigh, decide — is exactly the move Paul says cannot reach spiritual things. The context is the cross itself (1 Cor 2:2, 1 Cor 1:18), not some elite layer above the gospel. Then ask: "How does a natural man become spiritual? Jesus tells Nicodemus in — he must be born again — and says that birth is from God, not from the will of the flesh. So by your own epistemic lights, before the new birth you cannot evaluate these things." The question that lands at the door is simple: "Have YOU been born again?" If not, Paul says you are the natural man he is warning.