Bhagavad Gita, Chapter 5, Verse 17

Those who have their intellect absorbed in That, whose self is That, whose steadfastness is in That, whose consummation is That, their impurities cleansed by knowledge, they attain to Non-return (Moksha).

Real, sustained focus in one direction is what actually gets someone somewhere permanent.

Krishna stacks several words here on purpose, intellect, absorption, faith, all pointing the same direction. That kind of full alignment, not a half-hearted effort, is what's described as genuinely lasting.