When pressed by orthodoxy, Jesus reportedly said what is in Matt 22:37-40, summarizing the law (Pentateuch) and the prophets (Ezekiel, Isaiah, et al). Those two commands were never at the heart of the teaching of imperial Christianity, the rump faith that resulted after the gospel reached Rome. Regardless of deity or if there is a God, well understood, those were not bad command (and if no god, you certainly aren't one and do not speak for one).
"Do unto others etc" predates Christianity and is all that is or was ever needed. The rest are attempts at co-opting and using moral reasoning to gain power over others.
As for self-identified Christians, the universality of the command to love thy neighbor is where you can always, always show them to be utterly self-contradictory in their ways and, in the final analysis, traitors to their own creed. Puffery is like that.