If you don't have a factual basis for your argument, then you have no way to know if you are 'moral'- you are instead basing it on your own ego what you may believe is right- but not necessarily what is actually right.
At that, if you are basing your 'morals' on falsehoods, your morals are more likely than not, also false.
All actions should be measured to be right and true, not just blindly followed based on ego. Imagine of a carpenter based his measurements on his beliefs versus what he could factually measure.