Upasaka means devoting to a particular god or goddess throughout his/her life time. When a staunch devotee worships his favourite god by chanting the god’s names / mantras, on a daily basis, with full of bhakti in his mind, he is called as Upasaka.
Sri Ramakrishna was an ardent devotee of Kali Ma, and he performed pujas in the Dakshineswar Kali Temple, and served as a holy priest in the temple, and he used to chant various names of Kali Devi recite mantras and perform pujas in a magnificent manner, and due to that he is called as KALI UPASAKA.
The great Vishnu Devotee Sri Bhakta Prahladq used to perform pujas to his beloved god Narasimha and adorn him with flower garlands. He is said to have chanted the Narasimha Mantra, for several billions of times, and due to that, he is called as “NARASIMHA UPASAKA”.
The famous Nayanmar saints used to chant the “NAMAH SHIVAYA” Mantra continuously in their life, and hence they are called as “SHIVA UPASAKAS”, andsimilarly the Alvar Saints are known as “NARAYANA UPASAKAS. Bhakta Anjaneya Mahaprabhu is chanting the Rama Mantra from the Treta Yuga onwards, for countless number of times, and due to that, he is called as “SRIRAMA UPASAKA”.
Usually Upasakas would be having more power than that of ordinary humans. Generally they would utilize their powers for the well-being of the people, and they would pray to their beloved god, for our wellness, and they act as a mediator between us and the god. In this present situation, chanting the names of the gods/goddesses would bring good fortunes in our life, our sins would be drastically reduced, and we would be able to breathe easily in our life.
The great rishis and saints have attained higher positions in their life by the way of chanting the gods/goddesses names. Upasakas would attain a suitable position in the divine world, after their death, and they are free from the chain of birth cycles.
I am devotee of Guru Raghavendra, an incarnation of Bhakta Prahlada, and I am a Prahalada Upasaka. So far I have chanted lakhs of times of Prahalada Mantra, and due to that, I am living a peaceful life, without much sufferings in my life.