"You come together not for the better but for the worse" (1 Cor. 11:17)
Is this an unreasonable question?
My first point is that at least the Bible tells us to expect this. Most murder and persecution in the Bible arises from religion - all of it if you include as religion the idolatry of Mammon. Religion prompted Cain's murder of Abel. The false prophets raised persecution against Jeremiah. In the gospels it is not the whores and tax-gatherers but the Pharisees and scribes who pursued Jesus to his death.
In the United States today, it is pious evangelical church-goers who in every poll are most likely to approve of torture, undisturbed by knowing that this was the world's way of dealing with Jesus, and accordingly one of the main weapons of Satan that Jesus was raised from the dead to nullify. They are most likely to want to kill people in far-off countries that are minding their own business. They are the most inclined to hate and fear Muslims and to persecute them, just as their fathers were the most likely to hate and persecute black people. Westboro Baptist Church is a parody of American white people's Christianity, but like all parody, it is only an exaggeration, not something wholly different.
Whatever we're supposed to do with this, I'm confident of this much. If this is what the Bible tells us to expect from religion, then when we see it that way just as the Bible tells us it will be, the Bible is not proven wrong by proving to be accurate.
So what are some of the reasons to expect this?
Jesus reminds us that men spoke well of the false prophets, and that it is still that way. If you speak the truth they will persecute you, and if you want them to love you, giving them the lies they want to hear really works. Successful religion, what fills the pews, is about pleasing people. Since this priority is opposed to Jesus, it's not surprising that religion based on that foundation is not going to have Jesus around much, whatever the doctrine preached may be.
A related point, maybe just a restatement, is that successful religion is conformed to this world, and not least in the pretentious display of not being so - characteristic of the pride of life that is essential to the spirit of this world.
In fact, successful religion is drug-pushing - the drug being pushed being spiritual pride. Like all drugs, spiritual pride makes people feel good as it wrecks their lives, is expensive and brings much profit to the pusher, and keeps the addict coming back for more even though it hurts. Ecclesiastes states that one of the futilities in the world is that all activity is rivalry. All sorts of religious activity, tithing, and so forth, is the purchase of spiritual pride by documenting to oneself and others one's zeal for God.
If this is the hook that draws people in, it should not surprise us when spiritual pride abounds in religious congregations, just as I expect to see crack in a crack house.
This is the scene that Jesus saw in Judea and Galilee, but he still spent a lot of time in their synagogues. I went to church this morning, and I got a lot of help from the scripture reading, which concerned the golden calf they made because they wondered what had become of Moses. So I don't know what to do with church, but it's not so simple as either staying away or expecting anything good there.