Interesting.
Since I haven't listened to a lot of debates (except those with Professor John Lennox) I have no point of reference to discuss my views on them.
One Christian pastor (Jim Cymbala of Brooklyn Tabernacle) taught that we are born with an innate conscience, knowing the basic difference between doing right and wrong, and I agree. Still, "the devil is in the details" - quite literally.
As we grow, we go from power grabs over toys with our siblings to more consequential detours from morality and, more significantly, to various methods of justifying our hurtful and harmful behaviors.
As to the question of atheists - or simply people who are either agnostic or of either no belief system or some other philosophical mindset - everybody has the ability to do good based on their developed ethics or even any underdeveloped morality they may have.
To this point, I am remembering many beautiful classical orchestrations, the folk singers like Peter, Paul, and Mary, and even the romances in Rock 'n' Roll music. I can also remember how some of the latter music I use to enjoy became anathema to me when I really listened to the words...
Again, I don't know the debates you have heard or even if you perceived the arguments correctly. Neither do I understand why you are being admittedly facetious, because that is hardly a good "leg to stand on." It presents a fantasy and not a reality. In debates, I think they are supposed to start out with a "Proposed..." Right? The arguments relevant to the proposal are then presented. The veracity of the points made are then questioned and discussed before concluding arguments. Maybe you have put the cart before the horse?
Your concept of objective moral standard seems unreasonable to me, because outside of Humanity's Legal System of Law, there exists only subjective moral law, as proposed in "situational ethics." Still and all, when a cop issues a person a speeding ticket, a defendant usually has all kinds of reasons why he was speeding. However, the Judge has heard it all before and gives the offender a fine and points on his license - the latter having evolving consequences - like increased insurance premiums.
It's up to you, but I think your in that box I was talking about and riding that merry-go-round.
I still nold to the fact and agree with your premise that people don't have to be Christian to do nice things and to have some rudimentary measure of a conscience.
In conclusion, God, Jesus, and the Bible demonstrate real life ethics and morality in relation to Eternity and whether we believe of no, it remains the same... Everything a person decides to do has consequences - whether good or bad...