Epekteinomai is a compound: epi (toward) + ek (out) + teinō (to stretch). It pictures someone stretching their whole body forward, straining with every muscle toward a goal. It appears only once in the NT — in Paul's great athletic metaphor for the Christian life in Philippians 3:13.
This single word carries one of Paul's most vivid images of the spiritual life. "Forgetting what is behind and straining forward to what is ahead, I press on toward the goal for the prize of the upward calling of God in Christ Jesus" (Philippians 3:13-14). Epekteinomai is the posture of the runner in full sprint — arms extended, leaning forward, every sinew engaged toward the finish. Paul applies it to his pursuit of Christ. The word is a rebuke to spiritual passivity and an invitation to sanctified striving — not to earn grace, but to press into the fullness of what Christ has already secured.