A compound Greek verb meaning to contend earnestly, to struggle intensely, to fight on behalf of something. The prefix epi- intensifies the athletic/combat imagery of agonizomai. Used only in Jude 1:3 — believers are urged to contend earnestly for the faith once delivered to the saints.
Jude's single use of epagonizomai has rung through Christian history as one of the clearest mandates for theological conviction and doctrinal courage. The faith is a deposit — "once for all delivered" — not a fluid tradition to be revised by each generation. Contending for it requires the intensity of an athlete or soldier (agon, contest/struggle). This is not the ugly combativeness of divisive personalities but the beautiful courage of those who know what is at stake. Apostasy, heresy, and false teaching are not merely intellectual errors — they are threats to the souls of those the gospel is meant to save.