A friend of mine gave me several books recently, one was William Kelly's Notes on the Epistle of Paul, the Apostle, to the Romans. I've been excited to read this one for a while, and it has not disappointed.
I thought some of his comments on Romans 6 worth sharing at length:
Evangelicalism (whether in national or dissenting bodies) takes its stand (at least it used to do so) on the truth of Christ dying for our sins. This is most true, and a capital truth; without which there is no bringing of the soul to God, no divine judgment of our iniquities, no possible sense of pardon. But it is very far from being the truth even of the Saviour's death, to speak of no more now. Hence evangelicalism, as such, having no real apprehension of our death in Christ, never understands the force and place of baptism, is habitually infirm as to christian walk, and is apt to take the comfort of forgiveness by the blood of Christ so as to mix with the world and enjoy the life that now is, often helping on the delusion of ameliorating man and improving Christendom.
Mysticism on the other hand, whether Catholic or Protestant, dissatisfied with the worldly case and self-complacency of the evangelicals, is ever pining after a deeper reality, but seeks it within. Hence the continual effort of the pietist school is to die to self and so to enjoy God, unless perhaps with the few who flatter themselves that they have arrived at such a state of perfection as they can rest in. But for the mass, and I suppose indeed all whose conscience retains its activity, they never go beyond godly desires and inward strainings after holiness. They cannot dwell consciously in God's love to them as a settled fact known in Christ, producing self-forgetfulness in presence of His own perfect grace which made Christ to be sin for us, that we might be made the righteousness of God in Him. The system tends even in its fairest samples to turn the eye inwardly in a search after a love which may aspire to resemble as closely as possible the love of God, and so satisfy itself with the hope of a life ever higher and higher. Hence pious sentimentalism, which is little more than imagination at work in religion, reigns in the heart, not grace through righteousness.
Thus the ground the apostle here insists on is ignored by evangelicals and mystics; and indeed in Christendom at large it is excluded by its legalism and ordinances as decidedly as by rationalism. They are all, in every part, judged by the simple elementary truth couched under and expressed in baptism, that the Christian is dead to sin. To teach that we ought to die to sin is well meant, but it is not the truth, and therefore can but deeply injure the soul in its real wants. The true view is, no doubt, the reverse of death in sin; it is death to sin. Grace gives us this blessed portion — gives it now in this world from the commencement of our career — gives it once for all as the one baptism recognizes. Hence the Christian is false to the primary truth he confesses who should live still in sin. In his baptism he owns he died in Christ. He is bound to walk accordingly — as one already and always dead to sin.
Kelly, of course, says it much better than I could. But the two errors we see most often when it comes to our identification with Christ are: on the one hand, not recognizing the need for death of the old man; and on the other, the idea that it's something the believer has to do, rather than something God has already done. The one error seems to characterize evangelicalism, the other seems to characterize asceticism. But neither one is the truth of Scripture. We do not need to die: we have already died (Romans 6:11). But the old man and his world are not capable of entering the kingdom of God: there needs to be an entire transformation (1 Corinthians 15:50).