What is the purpose of the Vedas?

Vedic literature teaches one to engage in pure devotional serice. According to the nature and qualification of its so-called followers, Vedic literature has recommended various processes such as karma and jñāna. Due to the faults of these followers, various opinions have cropped up. Actually, the Vedas are the only evidence and the instructing spiritual master of mankind. On the account of misinterpretation, various opinions other than pure devotional service have been preached.