Haldane completes his understanding as to what it means for the Christian to be "dead to sin" in Romans 6:2.
"In proof of the correctness of this view of the subject, let it be remembered that the Apostle’s refutation, in the following verses, of the supposed objection, does not rest on the supposition that sin is mortified in himself and those whom he is addressing, or that they are released from any propensity to it, but on the fact of their being one with Jesus Christ. They are united to Him in His death, and consequently in His life, which was communicated to them by Him who is a ‘quickening Spirit;’ and thus their walking with Him in newness of life, as well as their resurrection with Him, are secured. These ideas are exhibited in the 3rd, 4th, 5th, and 6th verses. In the 7th verse, the reason of the whole is summed up, — ’For he who is dead (with Christ) is justified from sin;’ and in the 8th verse, that which will afterwards follow our being justified from sin is stated, — ’If we be dead with Christ, we believe that we shall also live with Him.’ Finally, in the 9th and 10th verses, the Apostle declares the consequence of Christ’s dying to sin to be, that He liveth unto God. The same effect in respect to the members must follow as to the Head with whom believers are one; and therefore he immediately proceeds to assure them, in the 14th verse, that sin shall not have dominion over them. The result, then, of the doctrine of justification by grace is the very reverse of giving not merely license, but even place, to continue in sin. On the contrary, according to that doctrine, the power of God is engaged to secure to those who are dead to sin — i.e., justified — a life of holiness, corresponding with that state into which, by their union with His Son, He has brought them.
"The full import and consequence of being dead to sin will be found, ch. 4:7, 8: — ’Blessed are they whose iniquities are forgiven, and whose sins are covered. Blessed is the man to whom the Lord will not impute sin.’ They who are dead to sin, are those from whom, in its guilt or condemning power, it is in Christ Jesus entirely removed. Such persons, whose sins are thus covered, are pronounced ‘blessed.’ They enjoy the favor and blessing of God. The necessary effect of this blessing is declared in the new covenant, according to which, when God is merciful to the unrighteousness of His people, and remembers their sins and iniquities no more, He puts His laws into their mind, and writes them in their hearts, and promises that He will be to them a God, and they shall be to Him a people. In one word, they who are dead to Sin are limited to Him who is the Fountain of life and holiness, and are thus delivered from the curse pronounced upon those who, being under the law, continue not in all things that are written in the book of the law to do them. The guilt of their sins, which separated between them and God, having now been canceled, they enjoy His favor, and all its blessed effects. It is upon these great truths that the Apostle rests his absolute denial that the doctrine of justification by grace, which he had been unfolding, is compatible with continuing to live in sin."Robert Haldane, Romans Commentary