Everyone has a worldview. Whether or not we realize it, we all have certain presuppositions and biases that affect the way we view all of life and reality. A worldview is like a set of lenses which taint our vision or alter the way we perceive the world around us. Our worldview is formed by our education, our upbringing, the culture we live in, the books we read, the media and movies we absorb, etc. For many people their worldview is simply something they have absorbed by osmosis from their surrounding cultural influences. They have never thought strategically about what they believe and wouldn't be able to give a rational defense of their beliefs to others.