Greek gnosis, from gignoskein, to know, PIE *gno-, which runs through English know, Latin cognoscere (cognition, recognize), Sanskrit jnana. Diagnosis (knowing through), prognosis (knowing before), agnostic (not-knowing): the medical and skeptical vocabulary all descends from the same knowing.
The modern market: gnosis as premium knowledge, the upgrade from belief. Huxley's agnostic, coined 1869 as a principled not-knowing, now sits in the same dictionary as the spiritual supplement aisle.
The Sanskrit twin jnana (knowledge, wisdom) kept the contemplative career that Greek gave the heretics: two continents, one root, both concluding that a certain knowing is the liberation. Sanskrit jnana, Greek gnosis, English know: the family reunion is a meditation retreat.
Is knowledge the cure, the disease, or the word for both?