No, Atheists Cannot Be Good Without BELIEF in God

In today's day and age, it is often contended, and very often contended by Christians themselves, that while atheists might not have a foundation for their moral values and duties, atheists can nevertheless be moral individuals without belief in God,--in the sense of being individuals who, though denying God, nevertheless follow an objective moral code of right and wrong and do, generally speaking, what is right--and yet, having thought about this matter for some time, I actually think that this contention is actually wrong, or, at the very least, not completely accurate, for consider that if the Triune God exists, and atheists do not believe in Him or acknowledge Him or give Him the worship that He is due from His creatures, then, in a very real sense, atheists are not being good, or at least not good in a very fundamental way, for they are failing to fulfill a critical moral duty / commandment that they should be fulfilling (namely, to love God with all their heart, and soul, and mind), but if, on the other hand--and for the sake of argument--we say that God does not exist, then atheists cannot be considered good in an objective sense either given that, on atheism, there are no objective moral values and duties that would allow us to call atheists 'good' in some real and significant sense, for while they might be trivially considered 'good' because they do what they wish and that is good to them, they cannot be seen as good in an objective sense, for there is no such objective good on atheism (a debatable point, I know, but one which I accept); and so, it seems to me at least, that atheists cannot be considered good without belief in God, at least not in a full and meaningful sense, for whether atheists are right or wrong about God's existence, the label 'good', in an objective sense, has trouble sticking to them either way, and so perhaps Christians should stop conceding the point that atheists really can be good without belief in God, for, as seen, a decent case can be made that atheists simply cannot be considered good without such a belief.