My Dear Sriman Vyas,
Please accept my blessings. I am in receipt of your letter dated July 14, 1970 and its contents have been carefully noted. Yes, you are correct when you say that for a true devotee of the Supreme Personality of Godhead Lord Sri Krsna theoretical speculations are avoided. Not only is devotional service the simplest way of God realization, as you have agreed, it is clearly pointed out by Lord Krsna in the Bhagavad Gita in every chapter that He can be achieved only by finally engaging directly in devotional service, or bhaktiyoga, the highest stage in yoga practice. In the First Canto, second chapter, verse seven of the Srimad Bhagavatam, it is clearly stated that by the process of applying devotional service unto the Personality of Godhead Vasudeva (Krsna), the immediate result is that causeless knowledge and detachment follow. Therefore the burden of useless theories can be avoided, simply by following the Sastras.
Anyone can understand that behind the beauty of nature, behind the succulent fruits and vegetables, and behind the wonderful heat and light of the sun, there is a Friend. So we should contact that Dearmost Friend, Krsna. Any reasonable man will accept this argument. That is rational thinking. In the second chapter of the Bhagavad Gita, Lord Krsna says that "One who restrains his senses and fixes his consciousness upon Me is known as a man of steady intelligence." Otherwise there can be no conviction. How can a man be convinced who will not accept? Krsna says hear from me, "tatsrnu."