Bg 17.1

arjuna uvaca
ye sastra-vidhim utsrjya
yajante sraddhayanvitah
tesam nistha tu ka Krishna
sattvam aho rajas tamah

Word for word: 
arjunah uvaca — Arjuna said; ye — those who; sastra-vidhim — the regulations of scripture; utsrjya — giving up; yajante — worship; sraddhaya — full faith; anvitah — possessed of; tesam — of them; nistha — the faith; tu — but; ka — what; Krishna — O Krishna; sattvam — in goodness; aho — or else; rajah — in passion; tamah — in ignorance.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Arjuna inquired: O Krishna, what is the situation of those who do not follow the principles of scripture but worship according to their own imagination? Are they in goodness, in passion or in ignorance?

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
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’s is to be cleared by Krishna. 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 Krishna.