The fifth of six summings-up that P T Forsyth gives in the sixth chapter of his book, The Work of Christ (pages 150/1)
What we have in Christ's work is not the mere prerequisite or condition of reconciliation, but the actual and final effecting of it in principle. He was not making it possible, he was doing it. We are spiritually in a reconciled world, we are not merely in a world in process of empirical reconciliation. Our experience of religion is experience of a thing done once for all, for ever, and for the world. That is, it is more than even experience, it is a faith. The same act as put God's forgiveness on a moral foundation also revolutionized humanity. Hence we are not disposed to speak of substitution* so much as of representation. But it is representation by one who creates by his act the humanity he represents, and does not merely sponsor it. The same act as disburdens us of guilt commits us to a new life. Our Saviour is his salvation is not only our comfort but our power; not merely our rescuer but our new life. His work is in the same act reclamation as well as rescue.
*Because substitution does not take account of the moral results on the soul, and for a full account of the cause we must include all the effects. To do justice to the whole of Christ's work we must include the Church, and in justification include sanctification. [Forsyth's own footnote]
For me this is one of the prime paragraphs in the book. While Forsyth goes into a lot more detail about what he's saying he, this is a wonderful summing-up of much of what he says.