The scientific method is a relatively new concept in history. Until the early 19th century there was nobody calling themselves "a scientist" but rather a "natural philosopher". Without the scientific method most educated people in the past could have approached "science" and religion with similar inductive and deductive reasoning making both really philosophical.
The main difference between religion and science now is how the "truth" is discovered. The scientific method gives a method of testing a hypothesis and it is a method by which anybody in principle can independently confirm the results. Religion is still largely philosophical because there is no formalized way a person from one religion can independently test another religion's conclusion.