I have observed the following:
a. When Christians share their ideas with each other, some will laugh at another person's views. They are so intellectually smug with their theology, they just laugh at the other person.
b. Christians often don't take too much time to explain their beliefs. They say that's just the way things are. And if you disagree with it, it's because the truth is not in you and you are on your way to hell.
c. Christians often don't know how or don't care to explain their beliefs. They are suspicious of the world and think there is no reason to have a strong argument because people will believe what they want. You should just laugh at everyone, basically.
d. Christians spit out theological terms one after another, but they can barely quote the Bible, or they have a few basic prooftexts that they can reach for whenever asked a good question. Christians have a hard time relation their theology and religious views to the Bible and seem to have a compartmentalized religion over here, Bible over there.
e. They are unable to weather trials. They seem to get very uncomfortable with the basic trials in life and very wishy-washy on the teachings of our faith. They don't inspire you as being people that, if things got really bad, would not sell out if that's what they had to do to survive.
f. Their willingness to pass judgment, or their willingness to cover up for their pastor's sins or their own sins, or a friend's sin. They basically use a crooked measure to make excuses when someone they care for does something wrong, or heinous, but they are always clear to call out what they see wrong about your life. Even when nothing is wrong, they search anything they can sniff out about a person, even if it's as silly as just disagreeing with them on a particular doctrine, for which they will then accuse you of not believing in the "whole Bible", "picking and choosing", or using the Bible for your own purposes.
g. They speak to others with such an air of cockiness, like they are great academics, in an ivory tower somewhere. Even when they have only a very basic education and are not scientists or very good academics at all. But the "Bible" gives every one of them a special area of expertise, and instead of acting as good stewards, leading sheep into light, they speak like the cockiest academic from graduate school, who steamrolled all the students with the superiority of his scholarship.
It's not even that these apply to a small minority. These are basic character traits that you will find in almost any Christian you talk with, any day of the week. Not one person is going to demonstrate all of these traits, but almost every Christian you meet will have at least one on this list. This is a huge problem. If Christians cannot talk respectfully about their beliefs without mocking the person sitting across from them, or mouthing some curse about them going to hell or being a worker of darkness, how will Christianity survive? How will Christians survive when they start seeing prophecy fulfilling itself in front of them, and they have to decide if they are willing to die for their beliefs?
Christians should be learning now while there is still time, to separate themselves from the world, to be not like the world, to not behave like they are of the world, the way the world ridicules, and mocks and scandalizes those who disagree with it. Or else they will have to learn this later, and a lot faster. We still have time now to practice these now and learn from our mistakes.
Corrie ten Boom, witness is perfected under trial. The Church must suffer the tribulation because it is so far from being worthy now to be received into God's kingdom. American Christians are living proof of that.