In the Fourth Adhyay, it is said that a person faithful to a particular type of worship gradually becomes elevated to the stage of knowledge.
ye sastra-vidhim utsrjya
tesam nistha tu ka krsna
sattvam aho rajas tamah
Arjuna said, O Krsna, what is the situation of one who does not follow the principles of scripture but worships according to his own imagination? Is he in goodness, in passion or in ignorance?
In the Fourth Chapter, thirty-ninth verse, it is said that a person faithful to a particular type of worship gradually becomes elevated to the stage of knowledge and attains the highest perfectional stage of peace and prosperity. In the Sixteenth Chapter, it is concluded that one who does not follow the principles laid down in the scriptures is called an asura, demon, and one who follows the scriptural injunctions faithfully is called a deva, or demigod.
Now, if one, with faith, follows some rules which are not mentioned in the scriptural injunctions, what is his position? This doubt of Arjuna is to be cleared by Krsna. Are those who create some sort of God by selecting a human being and placing their faith in him worshiping in goodness, passion or ignorance? Do such persons attain the perfectional stage of life?
Is it possible for them to be situated in real knowledge and elevate themselves to the highest perfectional stage? Do those who do not follow the rules and regulations of the scriptures but who have faith in something and worship gods and demigods and men attain success in their effort? Arjuna is putting these questions to Krsna.