If knowledge is the ultimate goal, what is the specific role of devotion, and is devotion by itself enough?

Within the framework presented in Chapter 50, devotion plays the specific and indispensable role of a preparatory agent. Its primary function is to cleanse the mind, which is 'soiled by Avidya' (ignorance). However, the text makes it clear that devotion by itself is not enough. It states that 'without that [knowledge], the power of Maya is irresistible, even with devotion to God.' This shows that devotion is the means, not the end. It's like the special collyrium ('Anjan') that, when applied, allows one to see hidden treasure; devotion removes the blockage of ignorance so that knowledge can finally dawn and be realized. It is the essential key that unlocks the door to knowledge.