It's not an analogy of church and state, it's the legal precident to AVOID a church and state analogy. The Bible isn't part of the discussion, if we want to consider the law, democracy, and Roe v. Wade. Yes, there are laws against murder, and Roe v Wade was agreed upon for a Federal law that legalized abortion, which is for the benefit of the living. If "life begins at conception", or with a beating heard, or with the first brain activity, or at the end of the 1st trimester, Roe v Wade confirmed that none of these definitions of 'life' can be applied to the law regarding abortion. Why separate church and state? Because you cannot legislate morality. You can however legislate criminal activity, which Roe v Wade determined did not apply to many abortions. Who had safe hospital abortions before Roe v Wade? Rich people. Who risked their lives with dodgy methods for illegal abortions? Poor people, and the middle-classes. Don't use a church and state analogy, unless you want to promote theocratic rule. And if you want a theocracy, look at the shitty situations theocracies are in. The vast majority of their constituents are absolutely miserable.