>what if the spirit of man is shaped by his technology
What if it isn't? Man no longer wars with trebuchets. Does that mean that the nature of man has changed? Similarly, man will someday set aside personal computers for something else. Does that mean that the nature of man will again change? A man's tools are not his nature, rather, nature is known through man's acts. Such acts are exampled in works such as Plutarch's lives or in the Meditations of Aurelius and speak just as true today as when they were written. Epictetus and the above cited wrote for the layman and require no arbitrator to make them pertinent or safe for the present day.
Recognize that there materialistic and idealistic worldviews, and further, that the the former is ubiquitous today. Try to see beyond the coloring of the present. Man's stuff is not the stuff he's made of. Capiche?
>what if the spirit of man is shaped by his culture?
Then one would benefit by looking outside of the prejudices of the present when reading for edification. Avoid marketing forces.
>There are no compelling reasons to believe in a god or gods. Atheism is the rational response to this state of affairs. Agnosticism is for the weak.
Atheists are really just closed minded agnostics. They are believers every bit as much as theists. Both are dogmatic.
Kant rationally discusses this in his Critique of Pure Reason. We have only five senses and a handful of a priori concepts with which to understand the world. All our knowledge is heaped up upon these principles of reasoning. In other words, what we know is fundamentally limited by what is used to know things. Objective certitude is far rarer than it is generally made out to be.
Beware of dogma, whether atheistic or theistic.