Rishabh Dev, also known as Rishabhanatha or Adinatha, is considered the first Tirthankara (spiritual teacher) of Jainism. He is a highly revered figure in Jain tradition and is believed to have lived millions of years ago.
Rishabhdev was the last Kulakar and the son of King Nabhi and Queen Marudevi. He was a popular king of Ayodhya belonging to the Ikshvaku dynasty. Upon reaching youth, King Nabhi arranged Rishabhdev's marriage to Sunanda and Sumangala. Sunanda bore him a son, Bahubali, and a daughter, Sundari, while Sumangala bore him 99 sons, including Bharat, and a daughter, Brahmi.
In due time, Rishabhdev renounced the world, handing over the kingdom to Bharat (Ayodhya), Bahubali (Takshashila), and his other sons as per their merits, and engaged in deep meditation after taking diksha (initiation).
During his spiritual endeavor, Rishabhdev fasted for a year, which was eventually broken by Shreyans Kumar, the grandson of Bahubali, who offered him sugarcane juice. After a thousand years of penance, Monk Rishabdev attained Keval Gyan (omniscience) and began his teachings. His first sermon was delivered to Bharat's son Marichi, who later became the 24th Tirthankar Mahavir Vardhaman in Jainism.
Once, Rishabhdev Ji, carrying a stone in his mouth and naked, roamed the forest. A forest fire erupted, and Rishabdev Ji perished in that wildfire.
Fom the above account it is clear that Rishabh Dev followed the following practices.
Renunciation of Worldly Life: Rishabh Dev renounced his kingdom, wealth, and family to pursue spiritual enlightenment. He adopted a life of asceticism, which involved severe self-discipline and abstention from all forms of indulgence.
Digambara Practices: As a Digambara (sky-clad) monk, Rishabh Dev practiced extreme renunciation, including the renunciation of clothes. This symbolizes the shedding of all material possessions and ego.
Deep Meditation: Rishabh Dev engaged in prolonged periods of meditation to attain inner peace and spiritual insight. Through deep meditation, he transcended worldly attachments and achieved Kevala Jnana (omniscience).
Severe Austerities: Rishabh Dev undertook severe austerities, including fasting and other forms of physical and mental discipline, to purify his soul and attain detachment from the physical body.
Fasting: He engaged in long periods of fasting, which is a significant practice in Jain asceticism. Fasting helps in reducing karmic load and achieving higher states of consciousness.
Bhagavad Gita chapter 4, verses 1-2, clarifies that, "O Arjuna, I imparted this knowledge of yoga, which is essentially the knowledge contained within the four Vedas, to the Sun. The Sun taught it to his son Manu, and Manu passed it on to his son Ikshvaku. Subsequently, this knowledge was understood by a few royal sages. Thereafter, this knowledge was lost to the world, becoming extinct."
Bhagavad Gita chapter 6, verse 16, states, "O Arjuna, this yoga (devotion/practice) is neither for those who eat too much nor for those who do not eat at all; neither for those who sleep too much nor for those who are always awake."
Bhagavad Gita chapter 17, verses 5-6 states, "Those who perform severe austerities without following the scriptural injunctions, torturing the elements in the body as well as the Self dwelling within, consider them to have demonic tendencies."
Rishabhdev did the following two practices which are against the ordinances of scriptures.
Noteworthy: Shri Rishabhdev Ji, by abandoning the scriptural practices mentioned in the Vedas and Shastras and engaged in arbitrary conduct based on personal whims. As a result he did not benefit from it at all.
From the above references in the Gita, it's clear that up to King Nabhi Raj in Satyuga, for almost a hundred thousand years, worship was conducted according to the knowledge of the Vedas. With his son, Rishabhdev, the practice of arbitrary conduct started, ending the tradition of Sanatani worship. The severe penance performed by Rishabhdev Ji is not the practice advocated in the Vedas. Hence, Rishabhdev Ji's devotion, by abandoning scriptural ordinances and engaging in arbitrary conduct, led to the destruction of his life. He did not achieve liberation. This narrative is found in the Shrimad Bhagavat Sudha Sagar (Sukh Sagar) Purana. As a result the whole of Jain community is following arbitrary practices which cannot bring about any relief, let alone liberation.