God reveals to a devotee in the form he wants to see or worship. He is one in all and all in one! Worship him as you like him, he will come to see you in the same form.

"Jaki rahi bhavana jaisi, Prabhu Moorat dekhi tin taisi"
God reveals to a devotee in the form he wants to see or worship. He is one in all and all in one! Worship him as you like him, he will come to see you in the same form. Shiva and Vishnu are not different. For the Vaishnavites, Shri Vishnu is Supreme and for the Shaivites, Lord Shiva is Supreme. God is One alone. The names and forms are imposed on God by the faith and belief of the devotees. Just as ShivaMaha Purana describes Lord Shiva as highest and supreme, similarly As per Rigveda, the lotus feet of Shri Vishnu are the supreme objective of the Demi Gods. The lotus feet of the lord are as enlightening as the sun in the sky". As per Shrimad Bhagvatam, Lord Shiva is the greatest of devotees of Shri Vishnu. It's true that Shri Vishnu resides in the heart of Mahadev.
"Shivaaya Vishnu Roopaaya Shiva Roopaaya Vishanave , Shivasya Hrudayam Vishnur Vishnuscha Hrudayam Shivaha. Yatha Shivamayo Vishnuhu Yevam Vishnu Mayaha Shivaha, Yathaantharam Na Paschyaami Thatha Me Swasthi Ra Yushi" ~ This shloka is found in the yajurveda. It can also be found towards the end of the yajurveda sandhyavanam. Vishnu's roopa and his avatar is none other than Shiva. In other words, Shiva is Vishnu. The one in Shiva roopa is none other than Vishnu. In other words, Vishnu is Shiva! Vishnu resides in Shiva's heart & Shiva resides in Vishnu's heart. Vishnu will be found in the same place you find Shiva and Shiva can be found in the same place Vishnu is. As is if you find one, you have found the other. We are one and the same!‪  Shiva meditates on Rama Nama, he worships Ram which is another roopa of Vishnu. "Sri Rama Rama Rameti, Rame Raame Manorame, Sahasra Naam Tat Tulyam, Rama Naam Varanane" ~ this verse is found in Vishnu Sahasranam where Lord Shiva says to Parvati, I chant the holy name of Rama, this holy name of Rama is equal to one thousand holy names of Lord Vishnu!! Likewise, Shri Vishnus level of devotion to Shiva is unmatched. Vishnu once brought 1000 lotuses and was placing them at Shivas feet; after placing 999 flowers he found that one was missing; he plucked out one of his own eyes and offered it as a lotus to Shiva; this supreme exemplification of devotion on his part was transformed into Sudarshana chakra in his hand, which he uses for protecting the world!!!
Well for me, Shri HariHara can never be separated, I live in Shri ShankarNarayana. And Shri ShankarNarayana live in me ~ All glories to the lord ~ Jai Shri HariHara ~ Jai Shri ShankarNarayana!!!
Happy Ekadashi Dear All !!!