Sat Kartar"Sat Kartar" is a sound that Guru Nanak, founder of the Sikh Path, (which many of our Kundalini Yoga mantras have come from) would speak, when things would happen, good or bad. His response was, "Sat Kartar!" and in effect he was saying, God or the Great Divine One, is the One doing this action, this situation. The "Sat" in the mantra is first identifying the Soul's True Sound(means Essence of Truth, or Being) It is said that directly behind the heart is supposedly where the Soul resides.
"Kartar" means Doer, and when the two words are combined, it is to say "Doer, Manifestor, or Walker of the Truth." When these primal sounds are repeated/affirmed over time, as a practice, we are in effect, opening,expanding, and directing the energetic FLOW of the Heart.
The second aspect of this heart-opening mantra is that it is a key to living in a state of Faith; we are calling our souls to walk, to experience, to do, in our lives with the belief and understanding that the Divine One is working in all situations. To experience the trusting, faithful aspect of love in our lives, we sometimes need to first do the work to open and trust the Flow of the Divine doing everything. When we open to that Flow then we establish and allow a path for the Universe to Flow back to us in response, with All it is waiting to give to us.