@freemo @cobratbq
Back to the original post: the actual argument most intellectually consistent religious folks make is that atheists cannot justify their morality. Not that they cannot act in a moral way without God/the threat of hell/something else.
In fact, if we take the Christian ethos, the crux is that nobody can merit salvation (including Christians) hence “being a good person” by human standards is insufficient to merit divine intercession on our behalf. Hence why salvation is called grace, or unmerited favor, and is a free gift that need only be accepted. Additionally, most people don’t argue that atheists are incapable of behaving in a moral way by human standards, as we believe that God’s moral law is written on the hearts/minds of everyone (the conscience) and serves as the way by which we can know right from wrong, thus, can obey or violate the moral law by making decisions based on our innate knowledge of it.
Additionally, (again, from the Christian perspective), it is not that we attempt to “be good people to avoid hell”, it is that we understand that we deserve hell (as all have fallen short of the glory of God), and that because of Christ’s sacrifice for us that we love Him, and it is our love for Him that drives us to keep his commandments. This is actually a critical distinction, particularly in my own life and faith, and within the Bible as well.
Finally, the justification point: either morality is objective or it is not.
If it is objective, it does not change over time: that is “thou shalt not murder” is universal for all people of all times, regardless of culture or other complicating factors. Then the question becomes, “what is the source of this immaterial, unchanging source of moral truth”? This, in many people’s view, points to God since many people have such a strong sense of the moral and immoral.
If morality is subjective, it is necessarily unjustifiable, as the changing whims of society, the ruling class, etc can then dictate what is and is not moral at any given time. Definitions of murder can vary, for example. Thus, the atheist is faced with the conundrum of being unable to condemn or affirm any given behavior as moral or immoral, only that they think it’s moral or immoral (or really it boils down to: I like that vs I don’t like that). This follows, because if we’re being logically consistent in a morally subjective universe, the conclusion is that there is no morality from which we can reference, thus everyone can behave as they want.
Of course, there are arguments for group-constructed/consensus morality, but these are fundamentally subjective as well, as they will vary as the group does.