Srila Prabhupada writes in Nectar of Devotion –
A devotee should start worshiping Ganapati, who removes all obstacles in the path of devotion. Once in this context,
a devotee asked Srila Prabhupada – Srila Prabhupada, if Sri Krishna only empowers demigods with different abilities then why does Nectar of Devotion prescribe Ganesha worship?
Srila Prabhupada explained-
“Krishna devotees worship all. Just like we worship an ordinary person if he gives us the facility to worship Krishna. Ganapati is also a devotee of Krishna. It is not required to worship demigods, but sometimes devotees did. Example: Gopis worship Katyayani(Durga Devi). They do not need it, but the social system was like that. But they pray to Mother Katyayani asking for an opportunity such that Shri Krishna can become their husband. The objective should be to achieve Krishna. People generally worship Durga Devi for material benefits. Dhan Dehi Rupi Dehi Yasho Dehi, the things we need in the physical world…
But the gopis did not worship for any physical object. They do it to attain Shri Krishna. In the same way, we can go to any deity. Why only Ganpati? All. But our prayer should be, please give us Shri Krishna. ‘ Then that prayer is right. “(Conversation held in Los Angeles on January 10. 1974 )