THE INFLUENCE OF SPIRITS IN OUR LIVES
Spiritism teaches about the coexistence of the material and spiritual worlds and the ways in which they influence one another. If you have read, in our web section on the scientific aspect of Spiritism, about the cosmic principle and derivative fluids, or "energies", that surround us, you have learned about how the thoughts of both incarnate and discarnate spirits affect the vibrational environment of both worlds, by imprinting their qualities on the spiritual fluids common to both realms, especially when considering the spiritual realms closest to Earth.
In addition to effecting one another by influencing the whole environment in general, spirits can, again through the will of their thought, exert direct influence on one another in much the same way. An excerpt from Kardec¹ explains how this works:
We should first consider that all beings, in both the physical and spiritual realms, are immersed in the cosmic principle that occupies space, just as we on Earth are enveloped by the atmosphere. The cosmic principle reacts to impulses of will, and thoughts travel through it as sounds travel through air. The chief difference is that, while sound vibrations are limited in reach, those of thought travel infinite distances in the cosmic principle. When a thought is directed at someone on Earth or in the spirit world, from an incarnate to a discarnate being, or vice-versa, a current of energy is established between them that transfers the thought from one to the other, just as air transmits sound waves. The power of the current is relative to the strength of the thought and desire. This is how spirits, no matter where they are, hear the prayers directed to them. It's how spirits communicate with each other, and how they send their inspirations to us. Finally, it's how incarnates can potentially establish (telepathic) contact with each other, even at a distance.
Looking at this kind of spiritual influence via thought transfer, we will focus here on the influence of the discarnate spirits on human beings. Question # 459 of "The Spirits' Book" asks, "Do spirits influence our thoughts and actions?", to which the spirits answer, "To a greater extent than you suppose, they can have a significant influence on both."
¹ "The Gospel"* Chapter 27, item 10