The first six verses of chapter eight reminded the Corinthian Christians that the knowledge they had was a consequence of their regeneration. Our knowledge of God is a reflection of His knowledge of us. Remember that God's knowledge of us and God's love for us are not separate things. God loves us truly because He knows us truly, and God knows us truly because He loves us truly.
Yet, from the beginning Paul pointed out that, though we all have knowledge of some kind, we all do not know as we ought to know. This concern is the continuation of the major theme of First Corinthians -- the wisdom of the world versus the wisdom of Christ. We have further identified this theme as the difference between Greek thinking, which is dualistic, and biblical thinking, which is trinitarian. Greek thinking is always necessarily humanistic because it cannot comprehend the true character of reality because it cannot see reality from God's perspective, the trinitarian perspective. Greek thought exists in a kind of dualistic world that can only comprehend two dimensions, where reality is more three dimensional -- trinitarian. It is the reality of regeneration that brings the perspective of the Holy Spirit -- of the Trinity -- to the minds of believers and opens their eyes to God's reality and truth.
In verse 7 Paul said that "not all possess this knowledge," reminding the Corinthians that believers are fundamentally different than nonbelievers. Believers are different than nonbelievers because Christian faith is real. This reality, this difference, is completely unbelievable and unacceptable to the unregenerate. The trinitarian reality is only available to those who are inhabited by the Holy Spirit. "If anyone has ears to hear, let him hear" (Mark 4:23). "Truly, truly, I say to you," said Jesus, "unless one is born again he cannot see the kingdom of God" (John 3:3).
And why is this true? Because it is not the flesh that sees or understands the things of God, it is the Holy Spirit. "He came to his own, and his own people did not receive him. But to all who did receive him, who believed in his name, he gave the right to become children of God, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God" (John 1:11-13). It is the Holy Spirit who inhabits born again believers, who sees the reality of the trinitarian God of Scripture, not the eyes of the unredeemed flesh.
Thus, Paul wrote, "However, not all possess this knowledge. But some, through former association with idols, eat food as really offered to an idol, and their conscience, being weak, is defiled" (1 Corinthians 8:7). Some of the Corinthian Christians who had formerly been associated with false beliefs and false gods (idols) falsely believed that there was some reality that was associated with the sacrifices and worship activities related to their former religious beliefs, like the consecration of food and holiday (holy day) celebrations. Though they now associated themselves with Jesus Christ, they had not made a clean break with their former beliefs. They brought many of those former beliefs -- false beliefs and the false worldview of Greek philosophy -- into the Corinthian church.
Consequently, Paul described them as having weak consciences. It is not insignificant that those who had been captured by the categories of Greek thinking were described as having weak consciences, of being morally weak. It is common knowledge that both Greek and Roman societies had little regard for what we understand as biblical morality. The fact that biblical morality was a non-issue to the Romans and Greeks can be seen in Paul's lists of behaviors and character traits that would not be found in the kingdom of God.
"Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men who practice homosexuality, nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God. And such were some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God" (1 Corinthians 6:9-11).
The Corinthians knew about the immorality of the Greeks and Romans because many of them were themselves Greeks and Romans. And it was precisely this mindset that was to be abandoned in Christ. This was the mindset that Paul described as morally weak and defiled. It was unrighteous, impure, immoral, degenerate, worldly, fleshly, limited, flawed, faulty and wrong. And Paul told them so every chance he could get. "Not all possess this knowledge" (1 Corinthians 8:7), he said. And he meant two things by it: 1) not all people possessed orthodox knowledge of God and Christ, and 2) not all Christians possessed it either. The whole problem in Corinth was that well-meaning Christians had brought their Greek thinking and Roman habits into the Corinthian church with them. This was the problem he was trying to correct.
For over 25 years Phillip A. Ross founded http://www.Pilgrim-Platform.org in 1998, which is loaded with information about historic Christianity. His exposition of First Corinthians in 2008 demonstrates the Apostle Paul's fierce opposition to worldly Christianity. Arsy Varsy -- Reclaiming the Gospel in First Corinthians, Ross's book, shows how Paul turned the world upside down.