Realation between Lord Ganesha,Muruga and Siva?

The following is quoates picked from Swami SubramuniyaSwami's Merging with Siva:

The gods are the controllers of the force-centers within man. They live in the innermost areas of form. To enter muladhara chakra, the aspirant must go through Lord Ganesha. And when the aspirant progesses through the manipura chakra, Ganesha will introduce him to Lord Muruga. Once this is accomplished, the devotee will worhsip Muruga as the Be-All and End-All, just as Ganesha was worshiped when the consciousness was in His chakras. Lord Muruga is the controller of the manipura chakra, the chakra of will power and two chakras above it, direct cognition and universal love. Now we begin to see that the aspirant has to proceed in to consciousness through the three chakras that Lord Muruga controls and meet all the tests before this God will introduce him to Lord Siva. Lord Siva’s chakras are number 6, 7 and beyond. The aspirant must go through the chakras of Lord Siva’s realm to become Sivaness – to experience His all pervasiveness and on in to the essence of all essences, Parasiva. The aspirant who dearly loves Siva should go beyond Siva’s personal aspect to reach the impersonal side and this is why when he finally emerges from Parasiva, he is truly a real bhaktar.