In the Bhagavad Gita, after having told Arjuna about dharma, Lord Krishna says Arjuna should surrender to Him. Krishna says “dharma samsthapanarthaya sambhavami yuge yuge — I will come in every yuga, to re-establish dharma.” Since He is dharma personified, we can say that He takes avataras, to re-establish Himself. This means that He makes it possible for people to observe His many auspicious qualities at close quarters. Because He came as Rama, we became aware of His simplicity, for He befriended people with a humble status in life, like Guha, for example. When He came as Krishna, He allowed Yasoda to tie Him up. Making His qualities known to all is what “dharma samsthapanarthaya” means, said M.A. Venkatakrishnan, in a discourse. If He had remained in Paramapada, how would the world have been witness to His qualities like sauseelya and saulabhya? Because He was approachable, most people did not recognise His Supremacy. They thought He too was a human being. Those who did not enjoy His qualities in His vibhava avataras, can still enjoy the same in His archa form.
In the first verse of chapter 4 of the Bhagavad Gita, Krishna says that karma yoga, about which He had been telling Arjuna, was told by Him to others too. He spoke about it to the Sun, who told his son Manu about it. Manu told his son Ikshavaku about it. Arjuna wants to know how Krishna could have instructed people who lived thousands of years before His time. Krishna then explains that His avataras are of His will. His many avataras are not like Arjuna’s many births. The Lord had not come to earth because of His karma. He knows what He did in His previous avataras. But can Arjuna know what he did in his previous births? Thus, the Lord explains to Arjuna the difference between His births and that of mortals.