I was at a youth ministry gathering at Forrest Hills Church a while back (because my boy Harrison Gillming was leading worship-don't forget to pick up his new album dropping soon - PLUG!!) and they were doing a series on Worldview Development. The main metaphor they used to explain what a worldview is? Glasses. A worldview is the lens through which you view the world. And here is the tricky part: It operates largely below the conscious level.
To develop the metaphor. Say you were born wearing glasses with pink lenses and you never took them off. To you the world would appear pink. In fact, when you looked at a white piece of paper it would appear pink. You wouldn't know that everything was pink; it just is what it is. But what if one day you took the glasses off? All of the sudden you would realize that there is another way to view the world. Maybe the unchallenged assumptions you held about reality would suddenly be up for a challenge. But then again, maybe not. Challenges to worldview level assumptions always stir up anxiety. People have a built in need for internal consistency in their views about life. Sure, most people's worldviews are not integrated and inconsistent, but this isn't a problem until it is pointed out. Then it becomes a big problem.
Here is an example of a Worldview assumption that most people never think about. Did you know that as Westerners we view time as a uniform linear progression and as a limited resource? Time is like a line moving from the past, through the present, into the future and it can be wasted. It makes sense to us to think about it this way. In fact this is one of the strongest vestiges of a Biblical Worldview that still permeates the worldview of Westerners today. But many cultures and societies view time as non-uniform and cyclical. Ever notice that time seems to speed up and slow down? Ever notice that so much of the world repeats in seasons? Some people groups work by event time. Now is the time to wash. Now is the time to harvest. Now is the time for the wedding. And some cultures separate divine time from human time. E.g. - Our universe will come into and out of existence as the dream of a deity.
And time is just one example. Now to the application. While the gospel cuts straight across worldviews, the message assumes as it's foundation the Biblical Worldview provided by the Old Testament. That's why, when Marcion wanted to toss the Old Testament books out of the Bible, he was condemned as a heretic. The gospel message makes sense in a particularly Jewish worldview. But most Christians today, do not hold the worldview of the Bible! We hold bits and pieces of it, but if you went to public schools and particularly if you went to university you probably have a uniquely American Worldview. And this is where a collision occurs.
Here is a summary of Naturalism (within an American Worldview) from Paul Hieberts' Transforming Worldviews:
"There is a sharp distinction between the natural and the supernatural world. The natural world is experienced directly through the senses and can be studied by means of the sciences and humanities. Supernatural experiences, on the other hand, are, for all practical purposes, confined to inner feelings, which cannot be empirically tested, or to miracles and visions, which are not seen as common, ordinary experiences and are, therefore, somewhat suspect. Few people, even those who are religious, live with a constant awareness that the world around them is inhabited by spirits that directly influence their everyday experiences. This living in a "natural" world is the basis of Western secularism."Two comments about the above statement. First, if you are a Christian please recognize that this is nowhere close to a worldview that is thoroughly based on the Bible. The primary distinction in the Bible is not between Natural and Supernatural but between Creator and all of Creation. Furthermore those things labeled as "supernatural experiences" are objectively verifiable in Scripture. That is the whole point of the Jewish Scriptures. God has intervened in his Creation, within history, and it is worth writing about precisely because it is not an inward feeling. The Red Sea parted! There was a huge pillar of fire! The walls of Jerusalem have been rebuilt! Jesus rose from the dead! And if you'd like proof you can talk to the people who saw him (1 Corinthians 15).
Second, you may completely agree with the above statement because you are not a Christian. To you I would add this challenge: The Bible makes an argument for a different way of looking at reality, but so does Indian culture, as well as Spiritists in Latin America and Africa. Assuming that you are correct is assuming that you have a privileged cultural position from which to judge the beliefs of most other cultures throughout all of human history. Naturalism is mostly a product of the anti-religious bias inherited from the Enlightenment in reaction to the 100-years War. The compartmentalization of religion into the "private sphere" is a relatively young invention in history and was useful to prevent the abuse of religion from negatively affecting public life. This is not a complete argument by any means, simply a thought to chew on.