I very much respect Sam Harris for taking the consciousness problem seriously. It poses a real problem to (his) atheism, and he, obviously, rejects the substance dualism, which would logically lead to a religious view on us.
However, without a conscious soul, meaning itself loses meaning. What's the ontological support for meaning to rise on?
One thing that is little known about Christianity (as an example) of the first millenium is its fierce fight with illusions, hallucinations and misleading spiritual experiences. Contrary to popular beliefs that religious spiritual experiences are quickly taken for granted for their emotional gratification, this was really not the case. Spiritual experiences were not looked after. They were not provoked. On the contrary. Great care was taken as to discern real experiences from illusory or, worse, misleading ones. The same goes with miracles.
Discernment, the ability to discern over what's real or not, was the most important virtue. Something that modern Christianity, in many areas, has lost. And with it, its credibility.