The Church is a hospital for sinners, something all of us are guilty of. Really, no one is better than anyone else. The only difference between us is that we sin differently. We are all in need of repentance and mercy.
However, our parish should also be our refuge. We should be free to pray there without any distractions. No mind games should be played in God's house, and no young children should ever be marginalized or excluded because someone doesn't like their parents.
Unfortunately, we are living in the world. We are also living in very sinful times. Sometimes, in a parish without strong shepherd, or a pastor greatly outnumbered by wolves, a very unhealthy form of lay leadership evolves. Since the parish is a community, it becomes difficult to isolate ourselves. Isolation may also not be good for your soul, because it can shut you off from the various devotions and practices that help you grow in your faith.
The trick is to stay involved, but not too involved, and to limit your dealings with highly disordered people, who may have their own agendas. Our Lord tells us to be both wise as serpents (discerning) and gentle as doves (trusting). This is a balancing act. On the one hand, we must assume the best possible motives of everyone we meet. On the other, we need to be realistic. Not everyone we meet at church can be trusted.
I've found that the holiest people are the ones who appear the most normal, and not overly pious, which may be a smokescreen for deeper issues.