I’ll use my mathematical pi example again. If person A uses pi to the 5th decimal place to solve their problem and, also, can not distinguish a difference in results for using pi beyond the 5th decimal place, did they solve the problem to you since they didn’t use the absolute value of infinity of pi? If all we can understand as “good”, “bad”, and all other subjective terms is pi to the 5th decimal place, then that becomes the current best solution to the problem until WE become convinced of why a value of pi at the 6th or any other further value is better. We are all the arbiter of what is the “good” in our reality since we can only understand the “good” by what we have been convinced of what is “good”. However, since we are all part of the human experience, we can have conversations with each other for where the universal overlaps of “good” are. That is where we start having grounding foundations of “good” aka: Human Wellbeing. Such as basic concepts of Life is preferable to Death, Health is preferable to Sickness, etc. We can argue over whether eating apples is better than eating pears for nutrition but it is universally bad, objectively bad, to drink battery acid; in reference to nutrition for Human Wellbeing. This is all grounded in a reality that we all experience and have access to the data. Not everyone has access to your deity and not everyone would be convinced that referencing a deity, once demonstrated to be there, should be the reference point for the “good” as well. Since we can not demonstrate that the deity is any different than an imagined idea of a deity or literary character, it’s irrelevant at this point. It’s no different than claiming your friend in the next town over, than no one ever meets, is your reference for X. That might be fine for you, but to everyone else, we are not justified in using your reference point since that person is no different than an imaginary friend to us.