Proofs that Shiva and Vishnu are Equal :
SB 4.7.54 ORIGINAL statement – Lord Vishnu tells King Daksha (father of Sati) – “He who of the three (Brahma, Vishnu and Shiva) having one nature, verily, of the Super soul in all beings, does not see the Separateness, o Brahman, realizes the peace.”
The same line is told by Lord Shiva to King Daksha in SHIVA MAHA PURANA.
Additionally, Lord Shiva also says
The foolish person who sees separateness among the three of us, definetely remains in HELL for the time as long as the moon and the stars are in the sky.
Daksha ! if a Vishnu devotee degrades lord Shiva and if a Shiva devotee degrades lord Vishnu, then both these types of devotees will automatically get all the curses that have been given to you and these types of devotees will remain devoid of tatva gyaan. i.e. the highest spiritual knowledge.
So, you can clearly see, if there had been any difference among the three, then Lord Vishnu or Lord Shiva would have mentioned it, but it is not so.
Similar Lines have been found in the RAMAYANA written by Goswami Tulsidas.
In the Lanka Kaanda, Lord Rama establishes the RAMESHWARAM SHIVA LINGA and worships Lord Shiva before proceeding on to the battle.
Lord Rama declares that – If a person degrades lord Shiva and calls himself my devotee and if a person degrades lord Rama/Vishnu and calls himself Shiva devotee, then that person is a fool, HELL resider and poor minded.
So these are the clear cut and transparent facts from the Main Hindu Puranas to which every person (male & female of every age group) of Sanatana Hindu Dharama accepts unconditionally.