Modern psychology is helping to feed these deluded ideas. It says we can never know absolute truth because all is relative. This argument can justify anything you like in that it completely does away with truth. Psychology holds that we see reality in different ways, and suggests that we have a right to do so - a right which should be respected. Yet I say again, people do not see reality in different ways. On the contrary, they construct entirely different realities out of their concepts, which have nothing to do with the real world. They have different ways of sorting out and surviving the mess in their brains, not different ways of seeing reality. They see a threatening and confusing world waiting to be tamed by thought, and are blind to the eternal Truth which requires no taming. Their ignorance of reality is inevitably harmful to society, and hardly deserves respect. Not only is their model of reality false; what it models is also false.
Indeed, all is relative. I only wish you would believe it! The reason you do not see the Ultimate Truth beyond doubt is because you continue to believe in your relative truths, despite having found them out!