C.H. Spurgeon: The Gospel is unclear without the imputation of Christ's righteousness

C.H. Spurgeon on the imputation of Christ's righteousness:

When we say that the righteousness of Christ is imputed to an believing souls, we do not hold forth an exceptional theory, but we expound a grand truth, which is so consistent with the theory of the fall and the plan of pardon, that it must be maintained in order to make the gospel clear. I think it was this doctrine which Martin Luther called the article of standing or falling of the Church. I find a passage in his works which seems to me to refer to this doctrine rather than to justification by faith. He ought certainly to have said, "Justification by faith is the doctrine of standing or falling of the Church." But in Luther's mind, imputed righteousness we, so interwoven with justification by faith, that he could not see any distinction between the two. And I must confess, in trying to observe a difference, I do not see much. I must give up justification by faith if I give up imputed righteousness. True justification by faith is the surface soil, but then imputed righteousness is the granite rock which lies underneath it; and if you dig down through the great truth of a sinners being justified by faith in Christ, you must, as I believe, inevitably come to the doctrine of the imputed righteousness of Christ as the basis and foundation on which that simple doctrine rests. (C.H. Spurgeon, The Lord Our Righteousness)