This is a very interesting symbolism- blood represents life, the very life force that flows thru the entire cosmos. Her blood stained tongue which is stained by drinking the blood of a demon (ignorant being- i.e. ego) shows that Kali can take away the very life-force of darkness and ignorance, so they are brought to nought! Using the chopper, she cuts off the head of the ego (false, ignorant, and deluded self) to liberate the soul from ignorance into her bliss of Divine presence and Truth. In this regard, Kali is the mother who creates all of creation. With respect to the parts which are caught in the delusion of separateness (Maya), she acts as the loving mother who annihilates the delusion and makes her child whole again- allowing them re-birth into her very being- as their higher, divine self.
It was always a scientific culture that understood the very mechanics and workings of this Universe. Their deities, their gods and goddesses were all a way of expressing and explaining these energies and their inter-working. Modern Quantum Mechanics is just starting to understand string theory, dark matter etc. which have all been fundamental to the Vedic understanding. Because of this, they developed ways and methods which allowed one to best tap into life-energy itself.
Vedic Culture, as it was practiced by the Himalayan Masters, was always a "way of life" and not a religion.
Their basic view was that, there is only ONE Supreme God-head (God as our creator) and each one of us can find our path to it- experience union with that divinity (Yoga) in their own way.
Because of this, anyone with any religious affiliations and beliefs can still benefit from their knowledgeable ways of Vedic Wisdom.
Our attempt here is to present this ancient wisdom in a modern light, so our readers can interpret the true, essential meaning more easily and then extrapolate it to their own specific scenarios and enhance the quality of their life and being-ness.