Because of their fellowship or association, with evil company, they were becoming involved in sin. Paul is suggesting that the people with whom the Corinthians were fellowshipping did not have the knowledge of God, and the Corinthians were being pulled down to their level. The apostle is saying in effect, "Break it off with those people. Get away from them. They are pulling you down. Repent."
He says, "I speak this to your shame." The people to whom he was writing had friendships primarily with people in the world. He is advising these people to consciously choose better companions.
John W. Ritenbaugh
What Is Prayer?
This well-known proverb is strategically placed in the Resurrection Chapter. In verse 32, Paul reminds the Greek Corinthians of an example of the perverse, immoral morass that they left compared to the liberating and ennobling calling God has so graciously given them. He then verbally punches them in the nose by telling them the company that they keep is destroying them, meaning they are gradually reabsorbing the attitudes and culture of the surrounding world. He then charges them to wake up to what they stand to lose by being too close to the world—even worldly people who might be fellowshipping with them at services but do not believe in the resurrection of Jesus Christ. Perceiving that some of them are on the verge of losing their salvation, he says, "Shame on you!"
The world's influences are, for the most part, subtle rather than overt. Being familiar to human nature, we find them easy to fall into or return to. What is the problem with the world? Its ruler, Satan, has designed it to lead people to live only for themselves. Therefore, we must fight and resist its attraction, which influences our hearts, because so much is at stake!
John W. Ritenbaugh
The Christian Fight (Part Two)
Self-indulgence leads to excessive striving for yet more worldly pleasure. For those whose chief aim in life is sensual pleasure, there is never enough to satisfy. Self-indulgence can lead to full-blown addiction. Without God's truth of the coming resurrections of mankind, men see no reason to refrain from a life of pleasure and dissipation, ending in death.
Martin G. Collins
Overcoming (Part 8): Self-Indulgence
Other Forerunner Commentary entries containing 1 Corinthians 15:34:
1 Timothy 2:3-4