This explanation by Hodge is among the best I've found capturing the tension of Christian life - namely the justified believer living under the consequence of Adam's sin. Exactly how is the Christian no longer under the "Law"? Hodge's answers is both clear and encouraging.
“To be under the law is to be under the obligation to fulfill the law of God as a rule of duty, as the condition of salvation. Whosoever is under the law in this sense, is under the curse; for the law says, ‘Cursed is every one who continueth not in all things written in the book of the law to do them.’ As no man is free from sin, as no man can perfectly keep the commandments of God. Every man who rests upon his personal conformity to the law, as the ground of his acceptance with God, must be condemned. We are not under the law in this sense, but under grace ; that is, under a system of gratuitous justification. We are justified by grace, without works. We are not under a legal dispensation, requiring personal conformity to the law, and entire freedom from sin, past and present, as the condition of our acceptance; but we are under a gracious dispensation, according to which God dispenses pardon freely, and accepts the sinner as a sinner, for Christ's sake, without works or merit of his own.
Whoever is under the law in the sense just explained, is not only under condemnation, but he is of necessity under a legal or slavish spirit. What he does, he does as a slave, to escape punishment. But he who is under grace, who is gratuitously accepted of God, and restored to his favour, is under a filial spirit. The principle of obedience in him is love, and not fear. Here, as everywhere else in the Bible, it is assumed that the favour of God is our life. We must be reconciled to him before we can be holy; we must feel that he loves us before we can love him. Paul says it was the love of Christ to him, that constrained him to live for Him who thus loved him and gave Himself for him. The only hope therefore of sinners, is in freedom from the law, freedom from its condemnation, freedom from the obligation to fulfill it as the condition of acceptance, and freedom from its spirit. Those who are thus free, who renounce all dependence on their own merit or strength, who accept the offer of justification as a free gift of God, and who are assured that God for Christ's sake is reconciled to them, are so united to Christ that they partake of his life, and their holiness here and salvation hereafter are rendered perfectly certain.”
Charles Hodge, Commentary on the Epistle to the Romans
