Logic soundly shows us that that which is "objective" is fundamentally inseparable from the abstract theories/models we create about it. In other words, it's ultimately not true that we can't really know anything. Consider, for example, that even calling something "objective" is itself an abstract theory of what constitutes objective.
It is commonly understood that the word "objective" in scientific terms translates roughly to "as objective as we can get in this life". Since no better standard is available to us, it makes sense to work with what we've got and not get too fussed about it.
Human Civilization will trod along slowly toward omniscience either way. And religion will die a slow death either way.