Christianity: Apart from the world vs. a part of the world
Christianity keeps picking things up from the world outside the church, then battles with the implications of these things as juxtaposed with its stance of being apart from the world. Christianity lets in psychology and becomes psychologized. Christianity lets in business and becomes commercialized. Christianity trains its missionaries like Amway salesmen - and people start seeing Christianity as yet another thing that people sell.
There is an obvious conflict here between Christianity's claim of being apart from the rest of the world and Christianity's interest in survival in the rest of the world. It adopts useful things from other places, but then the implications of these things come to roost and it often is not in the favor of Christianity. Thus, we are seeing psychology-trained people now saying such things as that Jesus was a sociopath, a narcissist and a histrionic, and we are seeing any number of other people having to reconcile such attitudes as "money talks, bullshit walks" and "you cannot serve God and mammon."
As these other paths influence Christianity, so does Christianity seek to influence other paths. You're a businessman? Become one as part of Christianity. You're a psychologist? Use your psychological knowledge to bring people to God. You're an artist? Produce Christian themed work. This influence goes everywhere. The Christians are much smarter than personality psychologists. They reach out to everyone and through this maintain their strategic superiority.
In fact Christianity has a long history of borrowing things from elsewhere. Christmas was dated to coincide with Roman holiday Saturnalia that took place around that time of the year. Easter is based on Babylonian goddess Ishtar, who represented resurrection and whose symbols were the bunny and the egg. Often "purifying" influences come into Christianity to rid of these "pagan" influences. For the most part, these people don't get very far.
In a religion that wants to be above the world and run the world at the same time, it is likely to find highly conflicting influences as function of this basic logical contradiction in the religion's self-description and purpose. When you start with militating against the world and then become the world, what's the rightful code of behavior? In many respects Christianity becomes victim of its own success. A religion that starts by fighting the world but then winds up running the world will be in a self-contradictory position, and that is not likely to bring about harmonious outcomes as to the course of action that it demands people to take.
How much of the Bible is about overthrowing oppression and fighting the world in the name of God. If you are born in a Christian area, the oppressors will be Christians. This begets a seed of constant disconsent, as one group after another fights to throw off the yoke of the world in the name of Christ - and finds as the yoke itself Christianity as it is practiced in their time and place.
Like Communists needed to constantly cultivate the revolutionary sentiment, so does Christianity according to its own pretexts need to constantly cultivate an anti-world sentiment; and this places fire under Christianity itself. The Communists kept directing this sentiment against capitalists abroad and against people inside their countries who were in any kind of disagreement with the party; and the Christians keep directing this sentiment against one or another aspect of the civilization. Whether it be artists, scientists, large businessmen, or the government, Christianity excels at persecuting everything else while itself suffering from a persecution complex. If Christianity had the complete obedience of the whole world, absolutely, it still would be engaging in this paranoid and persecutorial behavior and telling its followers to attack one or another group of people or for people to be pointlessly beating down on one another.
So here then comes the big contradiction: "World is evil" vs. "we, Christianity, want to run the world." When Christianity itself exercises a strong role in the world, its own scriptures will continue to teach it to treat the world as though it were evil. Which evil at this point becomes equal to Christianity and its leaders.
The saying about "you can't have a cake and eat it too" comes to mind here. You can't be apart from the world and be a part of the world at the same time. Christmas carols and plastic reindeer are things of the world, as is tele-evangelism and radio preachings and - yes - the Tea Party. Christianity needs to decide whether it wants to be apart from the world or whether it wants to run the world. It cannot do both.