An ethical position cannot be rationalized by a religious belief.

It is, fundamentally, a BELIEF.

A belief might make a person think something is wrong, and therefore unethical or immoral. But, it is still grounded in a belief.

If someone cannot successfully argue, without referring to spirit or soul or God's Creation, that a fully defined human being is created at conception, then we cannot get to the argument about the ethics of abortion.

A belief is insufficient for a morality.