Morality requires religion

Overview
Defenders of religion often claim that there can be no morality, or moral behavior, without the discipline imposed by religion.

This claim most often takes the form of a claim that morality requires God, but other aspects of religious discipline are sometimes invoked instead.

Conclusions
The objections to "morality requires God" generally apply to this claim as well, to the extent that the benefit of religion is presumed to be a threat/promise combination which gives people an incentive to behave decently and without which they would not do so.

If there are any arguments for this claim which do not invoke a threat/promise combination, we are not currently aware of them.

Later
Probably these two should both be subclaims of "morality requires external incentives", or something similar; then the "psychopathy" counterargument can go there.