Concentrating on the third eye for instance creates a link with an invisible network of energies which by mimetic behavior create a flow of energy between the spirit and the mind.
Meditation can as well be seen as a form of training. A training for the mind in which the life force is being strengthened.
Where does that energy input come from?
Here are a few concepts:
Energy comes from Shamballa or another invisible vast energy body.
Energy is being taken from other parts of the peronal mind and brought to the area of concentration.
Energy is being generated by an inner dynamic process. The body, mind and spirit becomes a dynamo.
Energy is being generated by connecting with an invisible network of energies.
Let's take the example of body training. When we use a muscle, there is a natural concentration of life force being brought to that muscle. If the exercise is repeated, the muscle will grow, expand, be cleared, etc.
Meditation is a concentration of energy being given to the etheric body. This is where the key is.
If it was just a thought, it would be kept within the mind circulation and stay a mental or emotional process.
But meditation is something more than that. This concentration of energy brings life in an area of the person where life is not usually coming.
The usual daily circulation of mental processes simply creates a frame in the mental and emotional body which does not naturally bring fresh energy to the chakras.
Why do we focus on the etheric body? Because this is a space or a part of our being which incredibly expands as we rise to new spiritual dimensions.
The etheric body is usually poorly energized in a human being.
When meditation occurs (specially in the form of concentration...), a certain area of the etheric body will be energized. If the focus is on the third eye for instance, energy will be concentrated in that area.
The whole point is to train the abilities of that specific chakra.
So, what is a chakra?
Chakras are etheric organs. They are our sensatory organs on the etheric level. They are as well connected with both our physical body and our mind body.
Most of what impacts on the chakras will create and emotional or mental reaction. Even though the chakra itself is an etheric organ, most of what happens in a chakra reflects on emotions and thoughts.
The situation is the same as with physical senses. A beautiful smell creates joy, pleasure. These are emotions. The vision of an architecture will generate series of thoughts, ideas about the way space is used, the material's qualities, or the esthetic balance.
Why isn't all that common knowledge?
The etheric body is simply not the main focus of human evolution right now. It could be in the future though. Take for instance the awakening of medical science and anatomy. Knowledge of anatomy became common only recently (a few hundred years ago!!). Before that, all our organs were functioning. We simply did not know much about them. The awakening of a new stream of curiosity, linked with technological advances allowed this incredible breakthrough.
At this stage, many people already heard terms like "aura" or "etheric substance", but somehow, the tools to systematically explore what is behind these terms are not yet fully available. In that field, what is known is based on beliefs or inner experience rather than scientific proof.
When focusing on our etheric reality, we actually focus on the next step of human evolution. It does not mean that the rest of our physical reality disappears, it means that we learn to be active in both realities at the same time.
Take a child for instance. The first thoughts in his mind can feel like an incredible opening. As children, we learn to structure our thinking abilities. We learn logical patterns. We develop our emotional potentials. The awakening of our etheric potential could follow a similar path of evolution.
It's only when we secure our activity on the physical level that we are ready to evolve into this new etheric dimension. We are talking here about the human race, not individuals.
An individual can focus its development on spiritual awareness, expansion of consciousness. We can do that before "completing" our full mental or emotional potential.
As a human race, things are different. The physical base of society needs to be fully secured before doors start opening more widely on the etheric level.
The physical based activity of human life can be seen as a training ground. During that time, ways to function together, respect each other space, develop healthy boundaries and respect of all human life form are being developed in human consciousness. The collective consciousness is being built in a way which allows humankind to flourish healthily and in accordance with evolution lines.
With the opening of the etheric awareness comes greater responsibility. Imagine again a baby crawling on the carpet. In the moment they learn how to stand up, a new set of boundaries have to be set up so that the "Chinese vase" on the shelf does not become a thousand pieces "Chinese puzzle".
This education process is what humankind is going through. We are learning by experience about the good or bad consequences of our behaviors. We perfect ourselves, step by step, aiming for some form of stability and harmony.
The vision of what is beyond these physical limits can be quite challenging. If we were confronted all at once with the reality of what is behind the scene, it could simply be too much. So, we get a few glimpses at a time. The window of our consciousness periodically perceives some greater vision.
New mental models are being built which express the perception of this inner reality.
Meditation is this narrow window into these inner worlds. It allows us to integrate the vision of what we can be. At this stage, we can see meditation as a training tool, as a strengthening of our inner potentials.