That religions, especially Western theisms, are rooted in specific historical and cultural circumstances does not of itself impinge upon their “validity.” The truth of a given belief depends upon the belief’s approximation to what is perennial, what is common and transcendent among all religions. Of course, the Western theisms have historically maintained that they are unique and exclusive, cutting off their ability to transcend local culture and society by being so rooted in history. It is left to mystics, saints, and sages of these traditions to pull the elements of belief and good will up, up to that level of the perennial and universal.
To the hermit or solitary, already disposed to minimizing the effects of society and culture on his/her vision of reality, the approach to the perennial and transcendent can be easier. The hermit or solitary is already disposed to thinking like a sage, even if not quite sagacious. By no longer depending on the social side of religion or theism, the nature of things drops foible human interpretation. Nature (or Tao or God) can speak directly to the heart and mind.
Though modern atheism is built upon rejection of the social and cultural premises of theism and religion, it does not share the perennial because it still needs the social and cultural context, the approval of history. Thus atheism remains equivalent to theism in its inability to transcend time and space. Nevertheless, many scientists, especially the prominent physicists of the early twentieth century, do pursue a transcendent view of the universe as the equivalent of sages of the past.