The first thing that comes to my mind when I hear “eternal life” is the idea of life unbounded by the threat or the reality of death. This semi-idyllic state attracts, encourages and draws us onward. This image though requires a divorce from our current state of being. Our death (or in the case of many popular theologies, the rapture) forms something like a semi-permeable membrane separating our lives from eternal life. Passing through this membrane moves us from here to there.
I don’t believe this really tells the story though. Eternal life is life with an eternal dimension. Eternal life connects us now with us then (or perhaps here with there). Connecting with God brings us into alignment with eternity. God infuses us with a special extra dimension. It changes the nature of our existing life, allowing us to live eternally even while facing the reality of our oncoming death. It changes our life now from a drive toward death to a life-filled expression in time.
Eternal life is not merely a promise to motivate us toward some future fulfillment. Eternal life empowers us to live now. Because we have eternal life, we live from eternity, imbuing the world with God’s power, presence, life, and love. It transforms us into agents of divine change, unbounded by the temporal nature of our day-to-day lives.
This is why God sent his son… that whoever believes in him should not perish, but have eternal life.