What is the most detestable thing a person can imagine happening to their church? A disregard of the scripture? A lack of mission? Triviality or a worship of culture? Moral corruption among church leaders or an unloving attitude? A lack of worship?
No, it seems that a great many fear the teaching of Calvinism. That is, the five points of Calvinism. The doctrines of grace. These things:
- Total depravity
- Unconditional Election
- Limited Atonement
- Irresistible Grace
- Perseverance of the saint
That is, you believe that:
- We experience first our depravity and need of salvation.
- Then we experience the irresistible grace of God leading us toward faith.
- Then we trust the sufficiency of the atoning death of Christ for our sins.
- Then we discover that behind the work of God to atone for our sins and bring us to faith was the unconditional election of God.
- And finally we rest in his electing grace to give us the strength and will to persevere to the end in faith.
Radical stuff, that Calvinism. Goodness knows where that could lead.
Not sure? Here are some things you could read to maybe give you a better idea.
Rockstanding 
That was true of the church I attend, Tony. When our new (young, restless, and reformed) pastor arrived, many left for that very reason.