Humans may crave absolute certainty; they may aspire to it; they may pretend, as partisans of certain religions do, to have attained it. But the history of science - by far the most successful claim to knowledge accessible to humans - teaches that the most we can hope for is successive improvement in our understanding, learning from our mistakes, an asymptomatic approach to the Universe, but with the proviso that absolute certainty will always elude us.
Just because there are qualifiers in science, that doesn't mean we aren't certain about it. By absolute certainty he seems to mean knowing something about the underlying nature of existence. But he is wrong about religion. He is the pretender, discarding philosophy and religion without considering their arguments. Just because science has procured much knowledge, doesn't mean that it is the only source of knowledge.