Ganesh's primary significance is his ability to remove obstacles from the path of his devotees. His presence in the Hindu religion is due to this idea of an obstacle. When his mother, Goddess Parvati, desired a centurion to ensure that her bathing would not be bothered, she created Ganesh out of the sandalwood paste that she used to bathe. The small Ganesh proved to be a very capable guardian for his mother. When her husband, Lord Shiva, approached and was stopped by the little boy, he was bested and angered by the guard, unaware that it was his son fulfilling his duty. Lord Shiva's anger was unabated and in a fit of rage, he beheaded the boy. Overcome with a combination of sadness for succumbing to his anger and fear for the anger of his wife, Goddess Parvati when she arrived to see her beheaded son, Lord Shiva found the head of an elephant and placed this head on the son. Along with this, Lord Shiva and all of the other deities in the heavens blessed Lord Ganesh as "superior to all the Gods." From this point, anyone who wishes to find peace in new ventures and wishes to find happiness in this life must pray first and invoke the blessings of Lord Ganesh.
Ganesh Chathurthi is the birthday celebration for the Lord. It is designed for Hindu devotees of Lord Ganesh to both celebrate his presence in their lives and for them to have the Lord take with them the sadnes in being, their obstacles, when he leaves. The birthday celebrations go on for 11 days. There is variance in the traditional elements of the celebrations behind Ganesh Chathurthi, but the basic elements have much to do in connection with Lord Ganesh. The fact that one of the elements of the festival is to create and construct Lord Ganesh idols is representative of Goddess Parvati's construction of her son. The idols are adorned with the typical long stemmed grass, reflective of what Lord Ganesh enjoys to have near his side, and there is a recitation of mantras or slokas that help to "breathe life into the idols," reflective of how all of the deities appropriated unto the Lord the strongest of attributes in order to grant him the exalted status he received. Another element that "feeds" the attributes of the Lord himself is the preparation of food. Lord Ganesh's large stomach is designed to swallow or digest the good and bad this life offers. To this end, devotees prepare some of the Lord's favorite food, such as modakas which are small dumplings made of coconut, jaggery, and brown sugar. For the duration of the festival, there are celebrations in terms of song and dance, as well as opportunities for new artists to display their talents, consistent with the idea that any new venture must be invoked through the Lord. The final day of the ceremony is the most powerful, where the idols of Lord Ganesh that have been worshipped are taken to a body of water and deposited there. The theory is that the Lord has to go back to his heavenly abode via water. At the same time, as Lord Ganesh leaves, he takes the pains and sufferings of his devotees with him, reflecting how Lord Ganesh truly is the God who removes all obstacles in the path of his devotees. In this, the Ganesh Chaturthi festival is reflective of the aspects and attributes of the Lord, himself.