There are many other sages, like Śaṅkarācārya, Gautama Muni, Nārada Muni, etc., to whom we are indebted because we take advantage of their knowledge. Similarly, we are obliged to our forefathers because we take our birth in a particular family, where we take all advantages and inherit property. Therefore, we are indebted to the forefathers and have to offer them piṇḍa (prasādam) after they are dead. Similarly, to the people in general we are also indebted, as well as to our relatives, friends and even animals such as cows and dogs who render us so much service.
In this way, we are indebted to the demigods, to the forefathers, to the sages, to the animals and to society in general. It is our duty to repay them all by proper discharge of service. But by the one stroke of devotional service, if someone gives up all obligations and simply surrenders unto the Supreme Personality of Godhead, he is no longer a debtor, nor obliged to any other source of benefit.
In the Bhagavad-gītā also the Lord says: "Give up all your occupations and just become surrendered unto Me. I give you assurance that I shall give you protection from all sinful reactions." One may think that because he is surrendering unto the Supreme Personality of Godhead, he will not be able to perform all of his other obligations. But the Lord says repeatedly, "Don't hesitate. Don't consider that because you are giving up all other engagements there will be some flaw in your life. Don't think like that. I will give you all protection." That is the assurance of Lord Kṛṣṇa in the Bhagavad-gītā.
There is additional evidence in the Agastya-saṁhitā: "As the regulative principles of scripture are not required by a liberated person, similarly a person who is engaged duly in the service of Lord Rāmacandra is also not required to discharge the ritualistic principles which are indicated in the Vedic supplimentaries." In other words, the devotees of Lord Rāmacandra, or Kṛṣṇa, are already liberated persons and are not required to follow all the regulative principles mentioned in the ritualistic portions of the Vedic literature.
Similarly, in the Eleventh Canto of Śrīmad-Bhāgavatam, 5th Chapter, Karabhājana Muni addresses King Nimi and says, "My dear King, a person who has given up the worship of the demigods and has completely concentrated his energy in the devotional service of the Supreme Personality of Godhead has become very, very dear to the Lord. As such, if by chance or mistake he does something which is forbidden, there is no need for him to perform any purificatory ceremonies. Because the Lord is situated within his heart, He takes compassion for the devotee's accidental mistake and corrects him from within." It is also confirmed in the Bhagavad-gītā in many places that the Supreme Personality of Godhead, Kṛṣṇa, takes a special interest in His devotees and declares emphatically that nothing can cause His devotees to fall down. He is always protecting them.