ethical decisions based on religious context?

In my medical ethics class, we are discussing the importance of religious context within the field of ethical decision making. 

John Finnis, author of "abortion and health care ethics", makes an argument that is based in a central way on Catholic thought. What role should religious principles and beliefs play in our ethical theorizing?

 Finnis argues that ethical theology in a manner that is quite independent of any religious premises. He supports that they are philosophical and scientific concerns that are decisively right for everyone but that they have nothing to do with our particular religious context. However, he does reference every human’s particular justifications of the four main principles: Autonomy, beneficence, non-malefience and justice.

I believe it is inevitable for our religious beliefs to play a large role in our ethical decision-making. Regardless of what you may believe about a particular god, many gods, or maybe no god at all, everyone has some particular considerations and specifications of what they believe about how the earth was made and what is in control of our destiny. Even if a certain individual does not claim to be “religious” at all, wouldn’t the choices pertaining to the context of what that person believes will affect where they go when they die have an impact on the moral obligations of that person?