What past humanity? There are hunter gatherer bands roaming around the Amazon right now. They seem to exhibit at least as much "upstanding behavior" as the evangelicals sloshing around the US.
Scandinavia is fairly secular and has many nice attributes, the US is off the charts in terms of religion, violent behavior, gun deaths etc. I don't see how irrational beliefs about burning bushes, virgin births, walking on water, resurrections result in "upstanding behavior". If this were the case evangelicals would be the epitome of "upstanding behavior", but they are not.