Bad Company Ruins Good Morals
The Greek author Menander, who lived from 342-292 BCE, wrote many comedies. In one such comedy, Thais, he wrote, “Bad company ruins good morals.” This line became a proverb in the ancient world. It even found its way into the Bible (through Paul, through God).
1 Corinthians 15:33 — Do not be deceived: “Bad company ruins good morals.”
I find myself captivated by this saying — I recognize two facets of it.
First, this is what your mother told you when you were a kid. If you hang out with the wrong crowd, you are going to get into trouble. We have probably all fallen victim to this ruse: An innocent night out with the boys (or girls) and the next thing you are explaining yourself to a stern police officer — and eventually your mother, too. Notice that the company ruins morals. None of us are amoral. We all have morals. It is not enough for me, as a father, to teach my kids good morals. I also need to teach them to be wise with their choice of companionship. I need to carefully — wisely — position myself with my company as well.
Second, we should be even more careful that we are not the bad company ruining others’ morals. Too often, to the chagrin of my parents, I found myself as the one ruining the morals of others. Again: I was not amoral — though perhaps immoral. When we hang out with the wrong crowd too much, we start to become the wrong crowd. When we are the wrong crowd, we ruin the good morals of others.
There is much recent talk about how Jesus spent time with prostitutes and tax collectors. Some use that information to justify their immersion into a worldly life. I myself have done so. This cannot be good. There is also a trend for those who claim to believe in Jesus to spend the rest of their life hanging out with others who claim to believe in Jesus. They completely avoid those who are lost. This, also, is not good.
The answer is obvious and lies, with so many other things, in having a balance. We must be mature and wise with the selection of our company. We must be obedient to the Spirit of God who we claim resides in us. These are one and the same: Obedience to God always results in maturity and wisdom.

I think you make a good point. Christ didn’t “hang out” with prostitutes and tax collectors, he spent time with them to win them over to Himself. He told the woman in adultery to go and sin no more. After he went to Zaccheus’s house, Zaccheus repented and paid back what he had stolen. The Lord’s purpose was to minister to these people, not to be like them. That should be our purpose when we find ourselves in bad company.