The capacity to understand life, events, things, and the world is directly proportional
to the level of spiritual evolvement of each individual.   The more evolved one is,
the more the individual can understand life and the world.
The less spiritually evolved one is, the more primitive, limited, and constrained
the individual is in understanding everything.
Everyone is unable to comprehend concepts and truths above their energy level
(that is the level of their spiritual evolvement), while able to comprehend those of their
energy level and lower - within the limits of their energy level.   For example,
a low-energy person can understand a knife.   Knife is a lower-energy tool, so this
low-energy person can grasp its meaning.   Because this person is a lower evolved one,
his understanding of the knife is of a tool that can be used for cutting, killing, and making basic
tools.   A higher-energy person can also understand that the knife can be used for cutting, killing,
and making basic tools, but because this person is more evolved, he can also understand that
the knife is also suitable for making beautiful art.   The low-energy person is more likely to use
the knife for violent purposes; the high-energy person is more like to use the knife for peaceful
purposes.
A low-energy person cannot understand high-quality nutritional supplements,
for example, because the high energy of the high-quality nutritional supplements
is beyond the energy level of the person, and thus beyond his grasp.   A higher-energy
person can understand the same high-quality nutritional supplements, because their energy
falls within the energy level of the individual.   The practical manifestation of this is that
the low-energy person rejects high-quality nutritional supplements and readily draws his
knife, while the high-energy person readily uses high-quality nutritional supplements
and keeps the knife in the drawer.
It is impossible to convince a person to accept something that calibrates above the energy
level of the person.   That is why "simple" people reject natural healing and call doctors
that use natural healing methods "quacks".   No evidence presented to these "simple" people
can change their minds.   It's not just that they wouldn't want to believe in the natural
healing methods; it's that they are not capable of comprehending them; to them it's a language
they cannot speak.   At the same time: every individual, regardless of how "simple", has
a source of Light (Love) inside them; it is possible for this Light to come through and
help the individual grasp the potential of a higher-energy concept, such as high-quality
nutritional supplements.   The individual still may not consciously understand the full impact
of the supplements, but the inner Light brings enough motivation to at least
use them and see what happens.   Once the higher energy of the nutritional supplements
enters the individual, it elevates his energy level, so his understanding catches up.
One big difference between lower energy (lower evolved) people and higher energy
(higher evolved) people is that the higher evolved ones are more open to new ideas, concepts,
and truths, while the lower energy ones are not.   It's like "simple" people erect walls around
themselves, while more open people keep their boundaries more open.

Note: by "simple" is meant "low(er) evolved" = "low(er) energized".