It is only natural that the grateful child should perform these same duties for the parents. However, gratitude does not necessarily imply reverence. And our Sages gave this mitzva an immense importance which seems beyond the scope of ordinary gratitude. The idea of partnership suggests that the parents contribution is more than physical or biological. The human spirit, the complete human being, is also formed with the participation of the parents.
Chasidic thought describes the parents conduct as creating a spiritual garment for the soul.
This human partnership with HaShem in the most sublime task of all, the breathing of a soul into flesh and blood, is an awesome responsibility for the parents, and at the same time should elicit in the child awe and reverence towards the father and mother. The verse which commands us to revere our parents also admonishes us to keep the Shabbat. Our Sages learned from this conjunction that honoring parents may not be at the expense of neglecting other Torah obligations. After all, the parent also is obligated to carry out the mitzvot. The fact that specifically the mitzva of Shabbat is chosen to illustrate this message suggests some inner connection between honoring parents and Shabbat.