Here is a snippet of a good article by Eric Rauch, worth reading entirely:
“Religion does not only deal with where you will spend eternity. Every person on the planet has a religion (in fact several of them), whether they realize it or not. When a woman makes a decision to have an abortion because she believes that it is only a “clump of cells,” she is making a religious decision. When a man chooses to euthanize his aging and decrepit father because of his low “quality of life,” he is making a religious decision. When two parents decide to work longer hours and make more money to put their child through college, they are making a religious decision. Any time we act on our beliefs—e.g., fetuses are not babies, quality over quantity of life, better education means a better job, etc.—we are acting out of religious (i.e.spiritual, not empirical) convictions, even if those beliefs have been shown to be 99 percent capable of predicting future events (which begs the question of cause and effect, but we’ll save that for another day!).
What do we mean by the word ‘religion’? It is “the binding tendency in every man to dedicate himself with his whole heart to the true God or an idol,” according to F. Nigel Lee. In this sense all men are religious because no man can escape being a man in the image of God created to worship and serve God, rebellious and unregenerate though he be. Romans 1:25 says, “For they [mankind] exchanged the truth of God for a lie, and worshipped and served the creature rather than the Creator…” Man is inescapably religious.”