Our assumption that existence is primarily physical, and that reality is that which is tangible, is not self-evident, natural, or inborn.
This sort of thinking (a spiritual phenomenon in itself) is based on cultural maxims that are taught to us.
From a very young age, we are taught that dreams, ideas, and thoughts are not real, and that What we say, think, and dream do not count.
In turn, we transmit to our children—not always in words—the notion that "reality" is that which can be seen and touched.
Our children get the message continuously, in both subtle and not so subtle ways: "If it does not exist in matter, it does not matter."
In our culture, if a small child breaks a cup, we scold him; if he cuts his finger, we are worried; but if a child speaks of his dreams and imaginations, we dismiss them as unimportant, and even more—as unreal.
In this way, we are unintentionally, but continuously, brainwashed into thinking that the spiritual is not very real, and therefore we discount it in many ways.
This education has many evolutionary advantages, mostly to cats, cattle, or apes, who have to rely on their senses and not on their thoughts (if they have any).
Whether it is helpful in the long run for human beings is quite doubtful.
When we ignore or discount the intangible, we are misleading ourselves.
If spirituality were only pondering about angels, we could ignore it, claiming that angels are of no interest to us.
As things are, we cannot ignore or rid ourselves of the spiritual aspect of our life, so long as we are conscious.
–Rabbi Adin Steinsaltz
From Simple Words, p. 56 by Rabbi Adin Steinsaltz