Purport

A human can attain Moksha by various methods like Jnana Yoga(Yoga of knowledge), Raj yoga(or Dhyan yoga), Karma Yoga, etc but the devotion (Bhakti yoga) is superior to all. This fact as been explain in Shrimad Bhagvad Gita at various places. The above Shloka not only reiterates that but gives exact details of why?
Bhagvan Shri Krishna explains in very clear terms that devotion(Bhakti yoga) is easiest among all methods to achieve liberation. But there is yet another benefit. Devotion is the only method by which one can attain Supreme personality Bhagvan Shri Krishna and reside in his abode, as it is been told in another Shloka
“bhaktya mam abhijanati”(sbg 18:55)
Only my devotee can know me [in totality]

Even those who follow other paths, Jnana Yoga, Karma Yoga, Raj Yoga have to include devotion at some stage to achieve supreme abode. Therefore it can be proven beyond doubts that Bhakti Yoga(devotion) is a superior method, easiest and most effective.