In the Ramayan in about three or four places, the glories of Lord Shiva have been described. Goswami Tulsidas Ji in the Divine words of Lord Ram says, “Without bhakti (devotion) to Lord Shiva, a soul cannot attain Me. One who criticizes Lord Shiva and thinks of themselves as My devotee, cannot attain Me even in their dream.” In this way, these and other verses in the Ramayan sing the praises of Lord Shiva.
The people who read such descriptions wonder, “For the attainment of Lord Ram, for the attainment of Shree Krishna, is it compulsory to do devotion to Lord Shankar?” No, it is not like that. We can do devotion by accepting any form of God that we wish as our deity of worship, whether it is Lord Ram or Shree Krishna or any other form that we like, and that too under the guidance of a Guru. And our Guru should be visible to us, in front of us, and a living Saint.
The glories of Lord Shankar have been described because during the time of Tulsidas Ji, in South and North India, there was great controversy amongst the babas in relation to their respective religious groups. The shaiv (worshippers of Lord Shiva) and the vaishnav (worshippers of Ram, Krishna or Vishnu) started fighting and physically abused one another. People started rumors about Lord Shankar, such as, “Shankar Ji is crazy, eats dhatura and madaar (intoxicants), lives with spirits.” Thus, Lord Shankar inspired Tulsidas Ji, “This is what you should write so that people will stop being critical of Lord Shankar.”
Out of all the Puranas, the Bhagwatam is the primary Puran. It is stated in the Bhagwatam that Lord Shankar is supreme amongst all the devotees of God. He is the devotee of Shree Krishna. Lord Shankar entered maharas and is already a svansh of Shree Krishna. Lord Shankar and Parvati Ji also descended many times as Shree Radha Krishna. It is known as yugavatar in every Dwapar yug. Thus, all the forms of God are one and the same.
This is a very extensive topic. However, if we are doing devotion to Shree Radha Krishna, it is not necessary to do devotion to Sita Ram or, Kacchapavatar or, Varahavatar or, Parshuram and many other descensions. We have to do bhakti to Shree Radha Krishna and our Guru, and as for the rest of the forms of God, simply accept them as a form of Shree Krishna, bow to them and respect them.
Devotion and roopdhyan should be done of Shree Radha Krishna and Guru only and also make sure that you don’t develop bad feelings toward anyone in the world. He is Bhagwan Shankar. Lord Shankar is most loving to Shree Krishna and Shree Krishna is most loving to Lord Shankar.