Lord Shiva has a very unique and significant position in the cosmic manifestation. In fact Lord Shiva is the most powerful, second only to Lord Vishnu. Shiva is an expansion of Lord Krishna. Revealed scriptures explain that Krishna has 64 qualities. Lord Brahma posses 78% of these qualities and Lord Shiva possesses 84% of these qualities. Since living entities are also like Brahma so they also possess 78% of these qualities but in lesser extent. None of them possess all 100%.
Srila Prabhupada explains, “The living being can never possess attributes like Shiva, Vishnu or Lord Krishna. A living being can become godly by developing the seventy-eight-percent transcendental attributes in fullness, but he can never become a God like Shiva, Vishnu or Krishna. He can become a Brahma in due course: - Srimad Bhagavatam 1.3.28 purport”
Lord Shiva has connection with the material nature but Lord Vishnu (or Lord Krishna) is transcendental to material nature. The position of Lord Shiva is very beautiful explained in Brahma – Samhita (Verse 45),”Just as milk is transformed into curd by the action of acids, but yet the effect curd is neither same as, nor different from, its cause, viz., milk, so I adore the primeval Lord Govinda of whom the state of Shambhu is a transformation for the performance of the work of destruction”.
The scriptures like Srimad – Bhagavatam, Brahma – samhita, Padma – Purana etc. explains the position of Lord Shiva in this universe.
1. Srimad – Bhagavatam (S.B) (12.13.16) states vaisnavanam yatha sambhu i.e. Lord Shiva is the best of the Vaishnavas, the devotee of Lord Krishna.
2. S.B (6.3.20) informs us that Lord Shiva is one of the 12 Mahajanas, the authorities on Vaisnava philosophy.
3. In S.B 4.24.76, Lord Shiva states that if anyone reads his Rudra geeta prayer then he will invoke the mercy of the Supreme Personality of Godhead, Lord Krishna.
4. Lord Shiva tells his wife that he drank hala hala, the poison which came out during the churning of the ocean, to please Lord Vishnu.(S.B. 8.7.40)
5. In Padma Purana Shiva tells his wife Sati,”sri rama rama rameti rame rame manorame sahasra namah tat tulyam rama nama varanane.” Lord Shiva clearly speaks here that he relishes chanting the names of Lord Rama.
6. Lord Shiva got bewildered when he saw the female form of Lord Vishnu, Mohini Murti. Lord Shiva later reveals that he is unable to completely understand the illusory energy of Lord Krishna. This is stated in S.B. (8.12.10).
7. When Krishna displayed his Universal form then Arjuna said: “My dear Lord Krishna, I see assembled in Your body, all the demigods and various other living entities. I see Brahma sitting on the lotus flower, as well as Lord Shiva and all the sages and divine serpents.” Bhagavad-gita (11.15).
8. During Lord Krishna’s pastimes in Vrindavan, Lord Shiva wanted to participate in the rasa – lila dance along with the cowherd damsels and he desired to become a gopi.
(Reference: Self – Manager by H.G. Radheshyam Das, President Iskcon Pune)
Braham Samhita (verse 10) clearly establishes that Lord Shiva derives his power from Lord Vishnu, “The person embodying the material causal principle, viz., the great lord of this mundane world [Maheshvara] Shambhu, in the form of the male generating organ, is joined to his female consort, the limited energy [Maya] as the efficient causal principle. The Lord of the world Maha-Vishnu is manifest in him by His subjective portion in the form of His glance.”
Lord Shiva is neither an avatara nor avesha and is also not in between them. Lord Shiva is the greatest demigod, even greater than Lord Brahma. He is the spiritual master of the entire universe. He has his own spiritual line (sampradaya) called the Rudra – sampradaya. At present this sampradaya is represented by Vishnusvami-sampradaya, or the Vallabha-sampradaya.