Churches, unfortunately, attract their share of difficult people. Although we are all sinners, and in need of God's mercy, there are people who sin in a way that makes them inflict great emotional harm upon others. It is very unfortunate when this happens, in God's house, because many of us are seeking a spiritual refuge, in order to follow Christ more closely in such a secular world. We do not expect to find rivalries at our parish.
Some church ladies, in particular, can be as territorial as male tomcats. Unfortunately, it appears as if churches attract people with personality disorders, who like to run things. They may not have any authority elsewhere, but they seize it at church, when the opportunity presents itself. It may come as a shock to realize that not everyone you meet at church is honest. Not everyone is nice. You still need to protect yourself from emotional predators, just as you need to do elsewhere.
Some of the most destructive people, I've found, are the proverbial wolves in sheep's clothing. They appear meek and mild. They may have some strange personality quirks, and act a little bit strange. (We tend to overlook eccentricities at church.) Female covert narcissists (the kind you may find in church) may even dress frumpy. So they're the last people you'd expect to be competitive and manipulative. This is precisely why they're so dangerous.
The best advice I can give you is not to get too involved with the personalities of a particular parish. Remain detached and prayerful. Be careful with what type of information you share about yourself. A covert narcissist will file this away, for future reference.
For a discussion of female malignant narcissism, please visit my Female Bullies blog. Above all, remember that Heaven is our true home. On earth, we can expect many trials and difficulties. So don't be too surprised when the devil causes dissensions at church.