Why did God not allow Paul to tell people what he saw and heard in heaven?
God did not allow Paul to tell people what he saw and heard in heaven because the human race would have worshiped Paul instead of God. Paul was only human and never sought worship. Therefore God placed a restriction on him, forbidding him to repeat what he had seen and heard, preventing idolatry.
Les explains that if God had permitted Paul to repeat what he had seen and heard, the human race would have worshiped him. Paul was just as human as anyone else and never expected worship from his converts. God therefore put a stigma on Paul, forbidding him to repeat his heavenly revelations, because knowing the human heart, God could not permit such idolatry. Les compares this to why Noah's Ark has never been discovered—if it were uncovered, the world would flock to worship it. Les also notes this occurred fourteen years back, early in Paul's missionary career, and that what Paul saw and heard in glory constantly sustained him during intense suffering, such as when he was whipped.