Swami Harshananda writes in his "A Concise Encyclopaedia of Hinduism" that the "Chakras" are not anatomical centres but subtle seats of consciousness or Divine Power. Works on Yoga depict the nadis called the susumna, the ida & the pingala as the most important conduits for the flow of pranic energy. They start from the root of the spinal column & end near the centre of the head. They are seven in number namely muladhara, svadhisthana, manipura, anahata, visuddha, ajna & sahasrara, the last being the ultimate experience. These are part of the Kundalini Sakti, which is likened to a coiled serpent lying dormant, until it is roused by appropriate yogic exercises. The Kundalini is similar to the Caduceus, a symbol of a staff with two serpents intertwined around it, which can be traced back to Mesopotamia (4000 - 3000 B.C.)
In St.Teresa of Avila's book, "The Interior Castle" (1577), she likens the soul to a diamond in the shape of a castle containing seven "mansions", signifying the journey of faith in seven stages to the ultimate union with God. First mansion is the soul's state of grace through humility. The second is the practice of Prayer. The third is an Exemplary life where the soul has an aversion to wordly life & has an overwhelming love of God. The fourth is a departure from the soul actively acquiring what it gains as God increases His role. The fifth is incipient union as the soul prepares to receive gifts from God. The sixth is time torn between favours from God & outside afflictions. The seventh is the ultimate union with God.
Here it can be noted that in answer to queries about the spiritual attainments described in "Sri Ramakrishna The Great Master" by Swami Saradananda, a direct disciple of the Master, the Swami said "Nothing beyond my spiritual experience has been recorded in the book." As the book is replete with various spiritual realisations, including the highest one of transcendental oneness, it sums up the Swami as a liberated soul.
Similarly, we find St.Teresa writing "Ask (that person) to read the chapter on the Seventh Mansion (the highest union with God) & tell that the writer (i.e., herself) has reached that point & has the peace which goes with it." So, irrespective of religious affliations, Saints have achieved the highest spiritual goals.