Answer by Dan Conine:
Net Future Usefulness.
Any species will survive based on whether its members contribute to their own future and the future of their environment more than they consume in resources.
In religious terminology, it isn't "righteousness" that matters so much as "service to God": being a contributor.
In idealist terminology, it is simply "paying it forward" in order to persist as a species.
Does this mean always being perfect or 'good'? No. It just means "more good than not".