There's an old Russian proverb: "Show me who your friend is, and I'll tell you who you are."
One consistent piece of advice Tammy & I repeatedly give to people we are ministering to, is to select healthy friendships. When we are reaching out or simply counseling with someone, we remind them of the truth that we will be like the people we spend the most time with. For new believers, we warn them of the need sometimes to find a whole new set of friends; leaving their old life behind them for "good". For people who are being drug-down, we point out the bad influences and the effects of the unhealthy people in their life. It seems like commonsense, but some people have a hard time recognizing what-a-hold the people around us have on us.
When our older boys were growing up, and for our younger two still at home, I have often quoted I Cor 15:33, which pretty much says: Do not be deceived, bad company corrupts good morals/character. Before they spent the night at a friend's house, we wanted to meet their friend & their friend's folks. If there was trouble at school, we asked who were they with. When they went off to college, we counseled them to find friends who were good students, not just good video-gamers... One of the hardest times of parenting is guiding your child away from a friend that will drag them down, it's hard but the pain is worth it.
The paradox here is, we are called to reach out to sinful people, but we need to steer clear of certain unhealthy people too. Well, it's not an either/or situation where we either spend all of our time at the Hog Wild Saloon or secluded and insulated in the Sanctuary.
Consider the time in Jesus' ministry when He was slandered for hanging out with the wrong crowd: "And as he reclined at table in his house, many tax collectors and sinners were reclining with Jesus and his disciples, for there were many who followed him. And the scribes of the Pharisees, when they saw that he was eating with sinners and tax collectors, said to his disciples, “Why does he eat with tax collectors and sinners?” And when Jesus heard it, he said to them, “Those who are well have no need of a physician, but those who are sick. I came not to call the righteous, but sinners.”" (Mark 2:15-17 ESV)
For us to share the good news with lost people, we have to be in constant contact with them. Yes, sinners. People who don't yet share our values. So, we spend time with people who would corrupt us? Aren't we risking violating I Cor 15:33? There's a difference between giving of yourself, and giving yourself away.
What keeps us anchored then? Acts 2:42 reveals several activities the early church engaged in, "And they devoted themselves to the apostles' teaching and the fellowship, to the breaking of bread and the prayers." It's easy to overlook, but the early church was devoted to fellowship. Prayers & Bible study, rituals like Communion, that all comes to mind easily enough when thinking about "church," but fellowship? Hanging out? Eating meals? Yes. I think playing board-games or grilling out together is equally as valuable for our development as hearing a sermon.
For any congregation to bond, it takes more than seeing the back of each other's head, in the pew in front of you. Also, there has to be a balance between service to community, worshiping, studying, and down-time. It's Biblical. It's smart. It's essential.