Do you know why anyone believes in belief, or in concepts, or in naivety, or in consciousness, or in identity, or in "it", or in "why", or in "randomly"?
If you don't, you don't have a sentence. As for "sentience"... Ha ha ha ha.
you have to laugh at the idea of not believing in anything, because it threatens your identity made of beliefs. i don't believe in anything, but i can still construct sentences with words, because i know what the common beliefs about words are. i don't necessarily believe in my own sentences either. as for "sentience", it is merely another concept, like consciousness, awareness, ultimate reality, truth, blah blah. upon direct inspection, one cannot experience any of these things other than to 'believe' in them. it is your choice to believe in them. i don't.