In the Bhagavad-gītā Lord Śrī Kṛṣṇa is depicted as the Absolute Personality of Godhead, and His last teachings in that great book of transcendental knowledge instruct that one should give up all other modes of religious activities and accept Him (Lord Śrī Kṛṣṇa) as the only worshipable Lord. The Lord then assured that all His devotees would be protected from all sorts of sinful acts and that for them there would be no cause for anxiety.
Unfortunately, despite Lord Śrī Kṛṣṇa's direct order and the teachings of the Bhagavad-gītā, less intelligent people misunderstand Him to be nothing but a great historical personality, and thus they cannot accept Him as the original Personality of Godhead. Such men with a poor fund of knowledge are misled by many nondevotees. Thus the teachings of the Bhagavad-gītā were misinterpreted even by great scholars. After the disappearance of Lord Śrī Kṛṣṇa there were hundreds of commentaries on the Bhagavad-gītā by many erudite scholars, and almost every one of them was motivated by self-interest.