“Christian hope is hope in God, for the God confessed by the Christian fellowship is ‘the God of hope’ (Rom. 15:13).
Christian hope and its activities have to be explicated out of faith’s apprehension of God and God’s ways with the world as its maker, reconciler and consummator.
In formal terms, this is simply an application of the rule that Christian moral theology ought not to exist in independence of Christian doctrine.
In material terms, it is an application of the rule that all Christian teaching, including teaching about the moral life, is an extension of the doctrine of the Trinity, which is the Christian doctrine of God. Christian hope is hope in this God; and the doctrine of the Trinity can therefore rightly be said to furnish ‘the environment of Christian behaviour’. How is this so?
The Christian confession of God as Trinity attempts to indicate that the sovereign majesty and perfection which is God’s life is that of the eternal and perfect relations of Father, Son and Spirit.
God is the relations of these three persons; his being is his eternal fullness as the Father who begets the Son, the Son who is begotten of the Father before all worlds, and the Spirit who proceeds from them. In these relations, fully achieved and lacking nothing, God is one; his unity is the repleteness and blessedness of the fellowship of the three.
This repleteness of God’s life includes within itself, as an integral aspect of its perfection, a turn to that which is not God. In this turn there occurs a movement in which the fellowship of the immanent life of God creates a further object of love.
This turn is free, self-caused, wholly spontaneous, original to the divine being; its necessity is purely the necessity of God’s own self-determination to be in fellowship with that which is other than himself. As such, it is not a turn which completes or extends the divine life; it is a turning out of fullness, not out of lack.
More simply: it is gift, love. This turning or act of love is the work of the triune God as the world’s creator, reconciler and consummator. It takes historical form in the simple yet staggeringly complex work of God’s majesty in the entire scope of the economy, as God brings creaturely reality into being, redeems it and ensures that it will arrive at its perfection.
As Father, God purposes that in its abundance, the divine love should be directed to bringing creation into being, bestowing upon it life, order and direction. Because it is rooted in the Father’s will, this purpose is unshakeable. That is, God’s relation to what he makes is not simply an act of origination, but an act which ensures the creation’s destiny, and therefore one which oversees, directs and protects the creation so that it attains that destiny.
As Son, God intervenes in the history of creation when by its own perversity the creature seeks to struggle free from the Father’s purpose, refusing to be a creature, and in so doing exposing itself to mortal peril. Only as creature can the creature have life; and it is the work of the Son to reconcile and therefore to recreate what has brought destruction upon itself.
Through the person and work of the Son, gathering created being to himself and bearing in himself its alienation from the source of its life and well-being, creation is reintegrated into the Father’s purpose.
Lastly, as Spirit, God acts to bring to completion that which the Father purposes and the Son secures against all opposition, namely the identity and integrity of the creation in fellowship with God. God the Spirit perfects, bringing creaturely being and history to their completion.
What is the significance of this for Christian hope? Hope is that creaturely disposition which corresponds to the fact that all occasions of human history, including its future, are caught up within the economy of the triune God’s mercy.
Because God is to the depths of his eternal being triune, and because he acts in the world as the one he is in himself, then the entire scope of human history and action is embraced by God’s purpose. God is not simply originator (setting the creation in motion), nor simply end (tying up the loose ends of history at its terminus).
Rather, as Father, Son and Spirit, God is infinite—no time or space is apart from or beyond his presence and action—and so steadfast—his purpose has been, is and will be at all times constantly and reliably at work.
And it is as this one that God is the ground of hope, for hope trusts that, because the Father’s purpose has been accomplished in the Son and is now at work in the world in the Spirit’s power, then human history is God’s economy.
Within the space which the triune God creates, hope is neither a fantasy nor a gesture of defiance, but a fitting, truthful attitude and shape for action. In sum: hope rests upon God’s faithfulness, and God’s faithfulness is triune.
One immediate effect of rooting a theology of Christian hope in the doctrine of the Trinity is to prevent an exclusive orientation towards eschatology. Hope is not simply a correlate of the divine futurity or the coming of God; it is, rather, a disposition which is related to the entirety of God’s dealings with his creature, past, present and future.
Within this, hope undoubtedly has an especial regard for the future horizon of human history. But this future quickly becomes isolated when not adequately related to a theological account of God as the world’s creator and as its reconciler in the person and work of Christ.
An isolated eschatology accords little weight to created nature, and often functions with only a pale theology of incarnation and atonement, precisely because the preponderant doctrinal weight is placed in the future of God.
This imbalance within the structure of Christian teaching orients hope, not to the fulfilment of God’s eternal purpose but to an absolute eschatological novum. The corrective to the imbalance is achieved by relating hope not simply to the future but also to the triune eternity of God, that is, to God’s sovereign and purposive presence to and action within all creaturely time.
Christian hope, and therefore hopeful Christian action, rests not simply on what will be, but on what will be as the fulfilment of God’s steadfastness as Father, Son and Spirit, his already-enacted, present and promised constancy to the creature.
Hope is hope in God’s steadfast love (Psalm 33:18, 22; 130:7; 131:3; 147:11). A Christian moral theology of hope begins thus with the perfection of the triune God.”
–John Webster, “Hope,” in Confessing God: Essays in Christian Dogmatics II, The Cornerstones Series (London; New Delhi; New York; Sydney: Bloomsbury T&T Clark: An Imprint of Bloomsbury Publishing Plc; Bloomsbury, 2016), 197–200.