I hope all of us agree with Karma theory. If bahunaam janmanaam ante .... vaasudeva iti mahaatma.... is true, then God Realization is not universal for every body in this very life. One soul must pass through many many stages to come to the Lord. One more thing... God cannot be limited to a form. If Krishna is present only in the "form of Krishna", then, Krishna is dead in tretaa yuga itself. Therefore, it follows that Krishna's spirit is Krishna. Jnaanis call that as Brahman and Bhaktas call that as Krishna Himself. To such Jnaanis, "dadhami buddhi yogam tam, yena maam upayaanti te", says Krishna. Both Jnani and Bhakta are reaching the same goal. Because of the love of Devotees, the God, assumes the form and for Jnanis, He is same as the Jnani. There is no difference between God and Jnani that time.