Bhagavad Gita, Chapter 4, Verse 10

Freed from attachment, fear and anger, absorbed in Me, taking refuge in Me, purified by the fire of Knowledge, many have attained My Being.

This path isn't new or untested, real people have actually walked it before and it worked.

Krishna points to precedent here, not just a theory being proposed for the first time. Letting go of attachment, fear, and anger, and turning genuinely toward this, is described as something that has already, repeatedly, led somewhere real.