A key is used to turn a lock which opens a door behind which we may find the treasure we are looking for.
Sometimes a teacher or a Guru gives his disciple a key but does not tell him where the lock is, which door the lock is on and what is hidden behind it. It may be that the disciple never finds the lock which the key could open and not knowing the value of the key, passes it down to his disciple who does not even know that he has been given a key to a great treasure. He thinks it is some talisman, something holy and instead of finding the lock, starts worshipping the key. He puts it on an altar, builds a temple around it and finds different ways to worship the key.
As time and generations pass, people from all over come to the temple to worship and ask the key which has now become an idol to exert its divine power in fulfilling their wishes and freeing them of disease. Many of our religious statues and artifacts are keys to great power and mystery but we spend our lives worshipping them instead.
Let us take the statue of Ganesha which is a symbol that opens the door to many inner mysteries. The elephant is the one animal whose trunk is both a sense organ and one of action; that is he uses the trunk to smell as well as move things around like a hand. This symbolises that he can use his hands at the same speed with which he senses.
Our speed of hearing or sight is very fast but our actions are slow. While Vyasji narrated the Mahabharata, Ganesha heard it and wrote it simultaneously. This means that there is higher knowledge within us which comes in flashes and half-dream states, and which if we do not write down immediately, we forget. Ganesha has a crooked trunk, Vakratunda. It says something about the way he breathes. He is the god of prosperity and happiness. So if we learn to breathe in a special way, we can also bring happiness and prosperity into our lives.
Thus if we use the key of Ganesha properly, we unlock the door to a vast treasure.