ShirdiSai is a divine avatar, but he has taken lot of births in his past. He lived a very pious, simple and a noble life, and acted as an example for others.
By studying the holy books and also by listening to spiritual discourses, we must be perfect in our life.
The great saints like Guru Raghavendra Swamy, Sri Shirdi Baba and Sri Ramakrishna Paramahamsa had been sent by the almighty to bless us, protect us and to remain with us for ever. They give food during the times of hunger and quench our thirst by giving water, and they are considered as the divine cow Kamadhenu, who is the giver of all kinds of prosperity to us.
Apart from the divine demigods, goddesses and saints, lot of guardian and village deities are there. Our Kula Devi/ Deva must be worshipped by us sincerely, since they are considered as our ancestors. Small children would be worshipping their Ishta Deva/Devata like Vinayaka, Muruga, Krishna and Ayyappan, and they get great pleasure in worshipping them. Some children would even do puja in their homes to the deities by calling their friends and would also offer the Holy Prasad to them, after the completion of the puja, which would be usually cooked by their mothers.
The great sages like Vasishta, Vishwamitra and Agastya can also be worshipped to get enlightenment in our life.
According to me, though there are lot of deities, the almighty is the only one, who is having supreme power, and who is taking different forms, to discharge his duties in a proper manner.