Divya Charitamrit

" Tulsidas ji has stated-Guru bin hoi ki gyan, gyan ki hoi birag binuu,
gawahin ved puran,sukh ki lahiya hari bhagati binuu

To simplify:

No knowledge can be gained without a Guru and also no knowledge can exist without detachment from worldly pleasures, there cannot be real happiness without devotion to God. So declare, the Vedas and puranas.