For hard-core maya-heads:
One concern that may arise in discussing monism in Saiva Siddhanta is that to accept an ultimate identity between God and soul (monism) would be tantamount to adopting Adi Sankara's (788-820) Advaita Vedanta philosophy. In fact, the pluralistic arguments above were originally formulated as a refutation of his Vedanta. This concern can easily be allayed. Saiva Siddhanta and the Vedanta expressed in the Vedas are not two irreconcilable views. Tayumanavar sang, "Vedanta is the fruit on the tree of Siddhanta." Satguru Siva Yogaswami taught us that "Siva is the God of Vedanta and of illustrious Siddhanta," and "Vedanta and Siddhanta we do not see as different" (nt. 166, 41, 64, 87). Monistic Saiva Siddhanta embodies both Siddhanta and Vedanta. More precisely, Vedanta is the summit of the vast mountain of Siddhanta; monistic Siddhanta is the whole, and Vedanta is the part, the highest part of that whole. Here we speak of Vedanta not as the denial of all but the Absolute, as in Sankara's view, which regards maya, meaning the entire manifest creation, including the soul and its evolution, as an illusion. Rather, we speak of the original and pristine Vedanta of the Upanishads, a perspective that accepts maya as Siva's grace in form rather than deluding appearance. To the Siddhantin, the world is Sivamaya ("made of Siva"), God's gift to mankind. While Advaita Vedantins hold that the world is nothing but maya (by which is meant illusion) and the greatest obstacle to Brahmavidya, "knowledge of God," Siddhantins see this world as Siva's gracious way of leading us to union with Him.
Let me elaborate for a moment on these two perspectives on maya. One is that maya is illusion, that this world is merely an appearance and not ultimately real at all. The other is that maya is God's loving creation, real and important for our spiritual progress. Devotees ask, "Which is correct? Can it be both?" In every aspect of the path there is the highest and the lowest and the in-between look at things, depending on where you are: on the mountainside, on the top or at the bottom. From Absolute Consciousness, maya is illusion, this is true -- an illusion to be disregarded, a barrier perpetuating the all-pervasiveness of consciousness which, from an even higher realization, is also an illusion. We are speaking of the contest between Parashiva being the Absolute and Satchidananda being the Absolute. So, the dual, dual/nondual and the nondual are the yogi's frustration in these higher states of mind. Once timeless, causeless, spacelessness is realized, all of this falls naturally into place. One sees form, time and causation as an illusion, a relative reality, and within it the mechanism of its own perpetuation of creation, preservation and destruction every microsecond, every second, every hour of every day of every year in the great cycles of time. This is maya. Its complexities are even greater than mathematical equations of all kinds.
So, you have a true/true and you have a true. True/true is seen by the Paramatman, the soul that has realized Parashiva. And the true is seen by the atman who has realized the all-pervasiveness of God. One is on the brink of the Absolute, and the other is the Absolute. Being on the brink of the Absolute is true, but being the Absolute and breaking the seal is the true/true. There you see all of the acts of Siva's play, in all of its many manifestations. Then there is the false/true. The false/true is understanding the true/true and the true, and being able to explain them intellectually but being devoid of experience. The true/true and the true are both of experience.
God Siva has endowed all creation of form with three of His powers, creation, preservation and destruction, and all life, as it is known, maintains itself. A flower creates, preserves and destroys. Microscopic organisms create, preserve and destroy. Because everything is not creating, preserving and destroying at the same time -- the process creates various densities of form, which we Saiva Siddhantins call relative reality. Those who don't understand the creative processes of Siva and the yoga processes of seeing through the ajna chakra, may consider the external world as illusory and a hindrance, or a temptation, to their desire for moksha. Therefore, they emphasize the concept of giving up desire, which is the desire to enter the illusory world and become part of the illusion, thereby giving up advaita; whereas monistic Saiva Siddhantins identify closely to Siva and, as an extension of His will, knowledgeably create, preserve and destroy, and understand themselves. Other organisms do likewise, but without being totally aware of these three functions.
I see maya both as creation, preservation and destruction -- and as illusion. The mechanism and the fact form the perspective of Parashiva. You have to realize that when the seal at the crown chakra is broken, the whole perspective changes and you see everything from the inside out, and you, to yourself, are the center of the universe. There is no doubt about it. And every manifestation of maya, which itself is manifestation, and the intricacies of anava and the complexities of karma can be and are seen through.