In the Divine Liturgy, shortly before the priest commemorates Christ’s actions at the Last Supper, he quotes some words of his occurring in St John’s Gospel, according to which God gave his only-begotten Son so that anyone who believes in him might not perish, but have eternal life (John 3:16). How are we to take the words ‘eternal life’ (Greek zoen aionion)?
You can’t attend the Liturgy for long without picking up its emphasis on life and on this as having been gifted. The Trinity is ‘life-giving’, the Holy Spirit ‘the giver of life’, the Cross is ‘precious and life-giving’. One of the titles of the Virgin is ‘the life-giving Spring’, and well known prayers refer to the Eucharist as ‘dread and life-giving mysteries’ and ‘pure and life-giving mysteries’. The Church seems to see itself, or perhaps experiences itself, as an organism pulsating with a life that has come from outside itself. And this is not biological life (Greek bios) but life of a different kind, in some sense spiritual life (zoe). One of the prayers just referred to picks up Christ’s words in the Fourth Gospel when it speaks of departing this life (bios) in the hope of eternal life (zoe). (The latter word is the one used in the Creed when it speaks of Christ’s coming ‘to judge the living and the dead’; presumably the two terms are not to be understood in a physical way.)
So perhaps we should think of eternal life not as the infinite extension of the kind of life enjoyed by everyone now, but as participation in the life of the One who is eternal. ‘It is the Lord Christ himself that is life, about whom John the Evangelist says “This is the true God and eternal life”.’ (Augustine, quoting 1 John 5:20)