“The secret of holy living lies in this doctrine of the union of the believer with Christ. This is not the only ground of his hope of pardon, but the source of the strength whereby he dies unto sin and lives unto righteousness. It is by being rooted and grounded in Christ that he is strengthened with might by his Spirit in the inner man, and is enabled to comprehend the breadth, and length, and depth and height of the mystery of redemption and to know the love of Christ which passes knowledge and is filled with all the fulness of God. It is this doctrine which sustains him under all his trials, and enables him to triumph over all his enemies, for it is not he that lives, but Christ that lives in him, giving him grace sufficient for his day, and purifying him unto himself, as one of his peculiar people zealous of good works.” — Charles Hodge, The Way of Life (1841), p. 330