When some people talk about Christianity, or any other belief, they give their ignorance away. I don't mean to be too harsh, just get right to the point. People discuss faith as if it was like being part of a club, which has some traditions and rituals, but it doesn't necessarily change your the members' world view. When they're not at a club meeting they simply live like everyone else around them.
This is the analogy that occurs to me. A convinced theist, or believer in God, and a convince atheist are as different as two mathematicians working with different number scales. If you work with a number scale of ten, then four fives equal twenty. If you work with a number scale of five, four fives equal forty. The same data yields a different answer if your analytical thinking framework is different. If a person really believes in the existence of God, then God is a factor in all things, all issues and all equations about life. God is always there and always has to be considered. And God can make the impossible possible. God can, if He chooses turn water into wine. So God has to be remembered in all situations. Someone I once knew said "This has nothing to do with God," when telling someone else what to do. They were quite wrong. It has everything to do with God. The advice they were giving was not in keeping with God's teaching. But they were saying that in the real world you have to be 'practical', by which they meant do whatever worked best, and never mind if it wasn't the Christian thing to do. There is probably a great deal of that. This person called themselves a Christian but left God out of some of their daily decisions in life. God was only for Sundays or for making fine sounding speeches about when they were in the mood. Their faith did not transfer into daily life.
That's not all. Some non-believers, or agnostics, don't understand why Christians get 'hung up' about certain things. They don't see why Christians have to make an issue out of things instead of just fitting in. That is to say, they don't realize how real God and His teachings are to those who really believe.
Even though I personally do not follow the teachings of Judaism, I must respect the right of a Jewish man to wear a yarmulka, if he feels that's important a part of his belief. Some people propose to ban such things in public schools, because the school is supposed to be secular. But a Jew does not stop being Jewish just because they are in a public school.
And a Christian does not stop being a Christian just because it is not Sunday and they are not in church.
That is why they sometimes cannot fit in with the world. Jesus Himself warned His followers of that. They may be rejected and victimised by the world.
In the same vein, some people say the church should 'modernise' to fit in with the community it wants to connect with. That is putting the cart before the horse. The community needs to change to follow the Word's teachings - or else be honest enough to admit that they are not doing so. To say the church has to agree with society is saying that the church has no real beliefs, it just reflects social or political fashion. But some people can't see that because they do not really know what they are talking about when they discuss faith.