Morality belongs to Science and Reason, not Religion or Individual Opinion

[The Wizard]

Morality is simply one or more groups' discourses put into an ethical sphere and labelled as such. The idea that there is one universal morality is deeply flawed (unless of course we add religion into the equation, but seeing as you have discounted that from the outset we do not need to cover it) because morality has changed so much as each society and social group's discourse has been changed. As the discourse changes so too does the morality, which in turn will affect all subsequent discourse and so on. I think you would be hard-pressed to find too many academics who disagree with this general statement, though they would probably frame it differently or along their own discursive lines (or that has been my experience at least).

Now, the entire field of science is based in Modernity, which is itself simply a broader social discourse that is commonly agreed on by most (if not all) of the major powerful discourses that most people ascribe to. As such looking to apply anything even resembling the scientific method to morality will only find what is considered the most moral thing from the point of view of a Modern society. As society continues to develop away from the search for an 'objective' truth (as it already is) and moves towards a Postmodern society or something resembling it, the morality that is discovered by this scientific method would be proven to be more and more vaunted as other, minor, discourses are examined and given voice and the major discourses change in relation to these and each other. Thus discourses would change and, again, so too would morality. This would only pick up pace as discourse pluralises, as it has for much of the last two centuries. So, ultimately, the search for an objective morality would suffer from general human advancement and would find itself quickly outdated and vaunted, a relic of a Modern age.

2 cents.

Sounds like a pretty radical form of postmodernism you're adhering to, here. That kind of postmodernism has its limits. Not everything is merely competing discourses, some discourses are worth less than others. Compare "Julius Caesar crossed the Rubicon" to "Martians control the White House". Derrida went a little too far to be taken entirely seriously if you ask me.

As for the OP, I don't think it's quite that bad. Surely the Church no longer has a monopoly on morality? Everything it says can, will, and is challenged. Every single day. As we speak, because that's what we're doing in this very thread. Though this is obviously still not the case in many non-Western societies.