The most significant difference between science and religion is that the former deals with empirical evidence, while the latter requires faith. (You can’t, after all, demonstrate the existence or nonexistence of God in a laboratory experiment.)
Falsification is the heart of scientific inquiry; no matter how fervently a scientist believes in a particular explanation of natural phenomena, if further experimentation disproves it, she alters that conviction. Religious beliefs by their very nature cannot be falsified.
Ideally, policy decisions, like science, are based on evidence; we try a policy approach, and if it doesn’t work, we try something else. The characterization of states as “laboratories of democracy” rests on that premise–states will try different approaches to similar problems, and others will learn from their successes and failures.
When political ideologies become religions, societies suffer. A recent post at Political Animal, made that point:
When Josh Duggar and countless similar self-righteous conservatives are exposed as cheating molesters, it doesn’t cause conservatives to question whether their belief system might be causing those problems. They just double down. When abstinence education causes more teen pregnancy than responsible sex education, conservatives double down on the slut shaming. When tax cuts on the rich and wage cuts to government workers lead to economic recession, Republicans don’t question their core economic beliefs; they just claim they weren’t allowed to go far enough.
In a way, modern conservatives are similar to the Communists of old. No matter how obvious the ideology’s failure, the response is always that the policies were not enacted in a strong and pure enough manner.
That inability to come to grips with failure and adjust course, and that insistence on doubling down in the face of adverse results, is part of why many consider modern conservatism to be an almost cultic movement. Its adherents long since stopped caring about the evidence or empirical results. It’s all about who can prove truest to the faith, and maximally annoy and rebel against the evil liberal heathens. Policies and results are really beside the point.