Liberation is our natural, free, spiritual condition, minus all the harsh conditions of material nature. In the material world, we're forced to endure repeated birth and death, old age, and diseases. We're not free. But in the spiritual world, where most people live, everyone is liberated—just as "out of jail" is where most law-abiding citizens are.
To become liberated—and stay that way—we need to get free from the mindset that keeps us in material bondage, which is, "I am this body and the world is mine to enjoy as I please." We're spiritual beings, and meant to act in harmony with the supreme whole, the Absolute Truth, or Krishna. If our actions are informed by spiritual knowledge, we're already liberated, for all intents and purposes, even while we're still inside material bodies.