Time, as Augustine pointed out, is utterly absurd. The past has van­ished, the future has yet to come, and the present is problematic. Only the tiniest indivisible instant can be called the present, and it flies from the future into the past imperceptibly quickly — for if it has any extension it is divided into past and future.

Yet time, with space, exists so certainly that it is the locus of our existence. There is consensus among authorities as diverse as Plato, the early Hebrews and modern physicists that time began with the uni­verse and will end with it.

If time is a difficult concept, how much more is eternity, the abode of God. Why should readers struggle towards the limited understanding that is the best we can achieve? Precisely because it is where God dwells; because it is our hope and our promise and our comfort.

The eternal God is your refuge, and underneath are the everlasting arms.Deut. 33:27

Eternity is a concept that belongs to believers; who else will ponder it?

People use the word in different ways — including the mutually exclusive infinite time and no time at all — but it always stands in contrast to time, expressing the transcendence of the limits of time.

The classical definition of eternity was given by Boethius at the start of the 6^th century: “the complete and total posses­sion of unending life all at once.” Our now, as if running along, makes time; the divine now, permanent, not moving and standing still, makes eternity. God is the same yesterday, today and forever, observed the writer to the Hebrews (13:8); in him there is no successiveness, no change.

If God is outside time, transcending time, it is incoherent to ascribe to him the limits of time — as, for example, open the­ists do in doubting his knowledge of the future. He doesn’t need a temporal tele­scope — our future is as open to him as our past, for it is all one.

But this does not mean God is discon­nected from time. Christian philoso­pher Brian Davies observes that the immutability of God is merely a negative description, telling us what God is not (i.e., not changing). But, just as when I teach someone must learn, and the change is in the pupil, so though God is unchanging he can bring about change in others. He can act, and he does.

Modern relativity theory invests time with the same sort of paradox as Augustine found, though from a different starting point. Einstein showed time is elastic, being stretched and shrunk by motion. The faster you go, the more time shrinks.

Past, present and future are not objective states. Physicists do not see time as a sequence of events which happen. Instead, all of past and future are simply there, and time extends in either direction from any given moment in much the same way as space stretches away from any particular place.

The relation between time and eternity is com­plex, but philoso­phers Stump and Kretzmann explain it well. (The illustration is demanding, but worth persevering with.) Picture two infinite parallel horizontal lines. The upper, representing eternity, is a uniform strip of light (where light represents an indivisible present). The lower, representing time, is dark everywhere except for a dot of light moving along it. As the dot of light glances on each portion of the lower strip, that portion of the lower strip is simultaneous with the whole of the upper strip. Because each dot location is simultaneous with the whole upper strip, each is simultaneous with precisely the same portion of eternal duration — that is, all of it.

But eternity, in Scripture, is not just the opposite of time, it is a state of being. Ecclesiastes 3:11 tells us God has set eter­nity in our hearts. The eternity of God’s dealings with mankind corresponds to something inside us: we have a capacity for eternal things, and a sense of something which transcends our immediate situation, the sensus divinitatis.

Despite his vast researches, Ecclesiastes’ author finds nothing in the finite earthly realm which can ultimately satisfy the human heart. Though he has resolved to understand “all” that is under the sun (Ecc. 1:13), he realises he can never comprehend God’s plan in its entirety. He understands what Augustine so beautifully summarised:

You have made us for yourself, and our hearts are restless until they rest in you.

Karl Barth describes three sorts of time: God’s time (eternity); our time, separated from the existence that God created by the fall; and the time of God’s revelation — the incarnation. “The word became flesh” also means “the Word became time”. In that revelation, eternity and time meet.

The eternal life promised in the New Testament, which those in Christ inherit and for which this world is a preparation (Rom. 5:21), is, literally, “the life of the age (to come)”. Like Plato, “the age” is con­trasted with chronos, the time created with the world. It expresses the longed-for blessings of salvation in the new heaven and new earth. It is life which belongs to God, a qualitative concept rather than tem­poral, though it will also be endless life.

John paints eternal life in contrast to the old, fleshly life. It does not just begin in the “future”, but is already the posses­sion of those in fellowship with Christ. In Christ, eternity has broken into time. As Kierkegaard observed, the eternal has sub­jected itself to the law of becoming, the All-Holy has taken upon itself the condi­tions of human existence, God has become man.

In the face of that towering, timeless truth, the Christian can only worship with Paul (1 Tim 1:17):

Now to the King eter­nal, immortal invisible, the only God, be honour and glory forever and ever.