If you desire to be pure, have firm faith, and slowly go on with your devotional practices without wasting your energy in useless scriptural discussions and arguments.
Good is that which elevates the mind and evil is that which degrades the mind. Social virtue and vice are temporal entities; they have nothing to do with your relationship with the Supreme.
Fasting in the monastic community is considered an ascetic practice, a “dhutanga” practice. Dhutanga means “to shake up” or “invigoration”. The Buddha, as is well known, emphasized moderation, the Middle Way that avoids extremes, in all things. Fasting is an additional method that one can take up, with supervision, for a time.
The faith of every man, O Arjuna, accords with his nature, Man is made up of faith; as is his faith, so is he. The threefold austerity practiced with faith by men of balanced mind, without any expectation of reward, is said to be pure.

