I have written on a piece of paper that I am alive. That is a correct and verifiable fact. I am indeed alive.
- Does this mean that I am now alive because this paper says so?
No.
Similarly, just because religion describes morality does not mean that it is the source of morality or that without this religion, morality could not possibly exist.
- If I rip the paper in two, does that mean I cannot possibly be alive anymore and thus die?
I assume you agree that this is not the case. So if we do away with religion, does this then mean that morality ceases to exist? The same answer applies: no.
Inferring that you're a religious person, does ripping up your religious scriptures mean that you are incapable of still being moral? Do you lose your sense of morality if you have not read your scriptures recently? I suspect you agree that this is not the case.
- If I had not written on this piece of paper, would I not have been alive now?
I assume you agree this is not the case. So if we had not created religion, would we therefore have no concept of morality either? The answer, just like for the piece of paper, is no.
Based on your question, I assume this is where you disagree. Your question is built on the premise that morality can only come from religion (or it at least asks to verify that this is indeed the case).
Let's explore your assertion. Let's suppose that without religion, morality cannot possibly exist. This leads to several consequences.
- Atheists therefore are either universally immoral, ...
I know many atheists who have a sense of morality, including those who have never been raised in any religious context. I am one of them.
- ... or they are faking their atheism by secretly still using religious morals.
I cannot conclusively prove a negative (whether they're faking their atheism or not).
However, if this is the case, it makes no sense to then call them atheists, as they are intentionally living by religious morality. They may not openly admit it, but this invalidates the claim that they are atheists.
- Animals have no cognitive capacity, no religion, and are therefore universally immoral.
If that were the case, then why do mothers of all species have an innate instinct to fight to the death to protect their offspring?
How are we able to tell a feral animal from a domesticated one, if not by observing that domesticated animals follow guidelines they have been taught? Is being a well-behaved pet not a form of morality?
Why do my pets specifically avoid harming me? If they are immoral, they should be wholly indifferent to me and whether they harm me or not. I'm not saying they should be actively trying to harm me, but they should at least be uncaring as to whether something affects me or not.
- One cannot change their sense of morality without altering the religious scriptures.
That is provably incorrect. Human morality has changed over time much more than any scripture has.
- Everyone who (genuinely) follows the same religion therefore has the same sense of morality.
I do not particularly know how to conclusively disprove this to you, I can only offer anecdotal evidence.
Consider yourself. Think about things you may find immoral (e.g. drugs, speeding, infidelity, domestic violence, ...). Have you ever met a person who follows your religion, yet did something that you find immoral?
Them having done so willingly proves that they do not find this act immoral, and therefore have a different sense of morality than you.
- Religion explicitly describes every facet of human morality.
Because if it didn't, then you would have to agree that some human morality was not prescribed by religion, and thus does not have a religious origin.
Consider a modern ethical issue: eugenics. The intentional genetic selection in order to create biologically specialized humans (or other creatures).
What is your opinion on the matter? Should it be allowed? Prohibited? Allowed but regulated? What would you consider as an unacceptable application of eugenics? What if I decide to genetically enhance my children to excel at combat, basically creating super soldiers? Do you think that crosses a moral boundary?
Once you've answered these questions, now please point to your religion's scriptures and explain why they explicitly include your moral stance on eugenics.
If you cannot, they this means that your moral opinion on eugenics did not come from your religion, it came from you.
- Atheists are unable to be prosecuted for their behavior (in a Western judicial system) as they are considered unfit to stand trial (insanity defense) as they are genuinely unable to tell right from wrong.
This clearly is not the case, or otherwise everyone would be claiming to be atheist when on trial.