Verse explainer
Almost everyone applies this to heaven — but Paul is quoting Isaiah to describe something believers already have access to right now.
But as it is written, Eye hath not seen, nor ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love him.
BSBRather, as it is written: "No eye has seen, no ear has heard, no heart has imagined, what God has prepared for those who love Him."
The plain meaning
Paul is mid-argument about the nature of the gospel message (vv. 6–10). He is not painting a picture of the afterlife; he is defending the wisdom he and his fellow apostles preach — a wisdom hidden from the rulers of this age (v. 8) but now disclosed. The Isaiah quotation (Isa. 64:4) is Paul's way of saying: this gospel was so far beyond natural perception that no unaided human eye, ear, or imagination could have arrived at it. Then he pivots immediately in verse 10: "But God has revealed them to us by his Spirit." The reveal has already happened. The "things prepared" are not exclusively heaven's rewards waiting in the future; they are the saving wisdom of God — the whole plan of redemption through a crucified Messiah — now opened to those who love him. Heaven may be included in the horizon, but the primary referent is present revelation, not future glory.
The common misreading
What the commentators say
Clarke argues firmly that Paul's quotation describes the present state of gospel illumination, not the future state of glory. The wondrous light, life, and liberty the gospel communicates to believers is what no eye had seen nor mind conceived. He notes the following verse seals it: the revelation has been made already, by the Spirit, to those who believe — making a strictly future-heaven reading a misplacement of Paul's argument.
JFB trace the quotation to Isaiah 64:4 and stress that Paul's point is the incomprehensibility of divine wisdom before its revelation, not the incomprehensibility of heaven before death. They note Isaiah addressed those waiting for Messiah as future; Paul addresses those who love him as having appeared — the shift from anticipation to present possession is the heart of the passage.
Gill focuses on verse 10's immediate follow-up: God has revealed these things by his Spirit. For Gill, the 'deep things of God' are the mysterious doctrines of the gospel — the eternal counsels and scheme of redemption — not merely beatific visions awaiting the redeemed in heaven. The Spirit's perfect knowledge of these things is what makes their communication to believers possible.
The word behind it
"To reveal" or "uncover" — used in verse 10, the verse that completes verse 9's thought. From apo (away) + kalyptō (to cover). Paul's whole rhetorical move depends on this word: what no natural faculty could perceive, God has now actively uncovered. The present-tense force of the revelation in verse 10 is what fixes the primary meaning of verse 9 in the present, not the future. Thayer notes it consistently denotes a disclosure of something previously hidden — here, the gospel itself.
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