We get an increase in spiritual knowledge and forces through hard work at esoteric exercises such as the ones described in How Does One Attain Knowledge of Higher Worlds? and in other books. But we must heed certain practical hints that help us to get ahead.
A healthy condition of tiredness doesn't have to prevent us from carrying out concentration and mediation with great willpower. On the contrary. Nature does one part of the work for us, since it dulls the outer sense organs and lessens our ability to take in sense impressions. For the goal is to see without physical eyes, to hear without physical ears and to think without a physical brain. It's precisely when we are tired that we can illumine and warm our being with the luminous thoughts of meditation.
Abstention from alcohol is necessary, for this works on the ego that lives and works in the blood. Meditation pulls the spirit up and loosens its connection with the physical body; alcohol pulls it down and consolidates it in the same. Eating meat makes the spirit heavy. Eating plants makes greater demands on the physical body so that it's busy and can't hinder the spirit's work. But what else is brought about by abstention of fish and meat? The bad about eating meat is the lasting effect of hurting and killing animals. These martyred animals return in the form of creatures who turn their forces against the bodies of the descendents of those who once killed them. Bacteria are re-embodied tortured, killed and eaten animals.
Exercises bring about changes in an esoteric that he must pay attention to if he is to avoid injuries. Firstly, the intellect changes; the guidance of thought becomes different and so does judgment and memory. It becomes difficult for an esoteric to give logical and readily understandable reasons for his actions to an ordinary man. Such grounds aren't at all necessary, for at the decisive moment a real esoteric knows the right thing to do. But if he doesn't pull himself together and lazily avoids doing thought-control exercises, his thoughts may get confused.
Some immature people force their esoteric development and gain a certain power over others; but at the decisive moment they're stopped before they can do greater damage.
Secondly the way one speaks and makes gestures changes. A man must have himself under control so that his nervous system doesn't take over and he does all kinds of impermissible things.
Thirdly the physical body must not become injured by a forced, greedy tempo in esoteric development, otherwise an acute disease may set in, which however is curable and that warns the one who get it.
In the Hebrew mysteries, they spoke of two men who tried to go through the temple's portal — but only one got to it. Only one developed normally through particularly patient and consequent methods and reached the goal. The others who forced their esoteric development were harmed. This shows how necessary a rigorous execution of the accessory exercises is for the harmonizing and consolidating effect on man's whole being.
There are many powerful meditation materials, especially in the Bible. For instance, there's a description of creation's six days, the words at the beginning of John's Gospel, the appearance of Yahweh to Moses in the burning bush, the Gospel stories, “I am the light of the world,” and a particularly effective meditation is 1 Timothy 3:16 in the following translation: The mystery of God's path can be known. He who revealed himself through flesh, although in itself his being is spiritual, who is only fully knowable by angels, but could nevertheless be preached to heathens, who is alive in the faith of the world; he is raised to the Wisdom Spirits' sphere.
What bodhisattvas could give to men was inspired by Spirits of Movement. The lowest things that radiated from the Christ came from the sphere of the hierarchy of the Spirits of Movement. The Christ is above all hierarchies — he belongs to the Trinity.