I know that Nara and Narayana were two avatars of Vishnu and their another birth are Arjuna and Krishna. Everyone knows that Krishna was an avatar of Lord Vishnu but Arjuna also? I am asking this question because if Nara was Vishnu,so Arjuna was also Vishnu?
Yes,Arjuna was an another incarnation of Lord Vishnu. Because if Sage Nara was incarnation of Vishnu,so this means Arjuna was also incarnation of Vishnu as they two was a power of Vishnu. In Bhagavat Gita Lord Krishna said ''I am Arjuna". What does it mean? See,Krishna was an incarnation of Vishnu and Arjuna also. So,this means that they two were same and if they were same,so they were incarnations of Lord Vishnu. Another reason is why Lord Agni gave the 'Gandiv' bow to Arjuna but not someone else. Because Sage Nara had fought with Gandiv bow in his previous birth and his next birth he was Arjuna. That's why Lord Agni gave the bow to Arjuna.