The Language of Duty

Duty is the language of moral obligation. Should the category of “duty” or obligation be rejected by the Christian on the basis of God’s grace revealed in the gospel? Not at all. In fact, the idea of duty actually permeates the Scriptures, which state that Christians are to be dutiful servants of Christ their master (Luke 17:10), and that our obligation (i.e. duty) is to be obey the law of love (Romans 13:8). Christians are called as disciples of Christ to do what he says (Luke 6:46 and Matthew 28:20). C.f. James 1:22-25. 

On this basis, the works of Reformed writers and the Reformed confessions are filled with the language of duty/obligation. 

Consider, for example, John Owen’s book, The Grace and Duty of Being Spiritually Minded. The idea is that spiritual mindedness is simultaneously a grace given to us by God and a duty we are called to cultivate—that is, we are to work up a sweat to be spiritually minded. John Owen also has a book called Duties of Christian Fellowship in which Christians are taught what their responsibilities are as members of the church—that is, what they are obligated to do in following God’s word and Christ as their master. 

Consider the way John Calvin speaks of the Christian life in his Institutes, “Even though the law of the Lord provides the finest and best-disposed method of ordering a man’s life, it seemed good to the Heavenly Teacher to shape his people by an even more explicit plan to that rule which he had set forth in the law. Here, then, is the beginning of this plan: the duty of believers is “to present their bodies to God as a living sacrifice, holy and acceptable to him,” and in this consists the lawful worship of him [Romans 12:1]. From this is derived the basis of the exhortation that “they be not conformed to the fashion of this world, but be transformed by the renewal of their minds, so that they may prove what is the will of God” [Romans 12:2].”

Consider, also, the many times the language of duty is stated in the Westminster Confession of Faith (WCF): 

“Men ought not to content themselves with a general repentance, but it is every man's duty to endeavor to repent of his particular sins, particularly.” (15.5)

“Their ability to do good works is not at all of themselves, but wholly from the Spirit of Christ. And that they may be enabled thereunto, beside the graces they have already received, there is required an actual influence of the same Holy Spirit, to work in them to will, and to do, of his good pleasure: yet are they not hereupon to grow negligent, as if they were not bound to perform any duty unless upon a special motion of the Spirit; but they ought to be diligent in stirring up the grace of God that is in them.” (16.3)

“They who, in their obedience, attain to the greatest height which is possible in this life, are so far from being able to supererogate, and to do more than God requires, as that they fall short of much which in duty they are bound to do.” (16.4)

“We cannot by our best works merit pardon of sin, or eternal life at the hand of God, by reason of the great disproportion that is between them and the glory to come; and the infinite distance that is between us and God, whom, by them, we can neither profit, nor satisfy for the debt of our former sins, but when we have done all we can, we have done but our duty, and are unprofitable servants: and because, as they are good, they proceed from his Spirit; and as they are wrought by us, they are defiled, and mixed with so much weakness and imperfection, that they cannot endure the severity of God's judgment.” (16.5)

“This infallible assurance doth not so belong to the essence of faith, but that a true believer may wait long, and conflict with many difficulties before he be partaker of it: yet, being enabled by the Spirit to know the things which are freely given him of God, he may, without extraordinary revelation, in the right use of ordinary means, attain thereunto. And therefore it is the duty of everyone to give all diligence to make his calling and election sure, that thereby his heart may be enlarged in peace and joy in the Holy Ghost, in love and thankfulness to God, and in strength and cheerfulness in the duties of obedience, the proper fruits of this assurance; so far is it from inclining men to looseness.” (18.3)

“True believers may have the assurance of their salvation divers ways shaken, diminished, and intermitted; as, by negligence in preserving of it, by falling into some special sin which woundeth the conscience and grieveth the Spirit; by some sudden or vehement temptation, by God's withdrawing the light of his countenance, and suffering even such as fear him to walk in darkness and to have no light: yet are they never utterly destitute of that seed of God, and life of faith, that love of Christ and the brethren, that sincerity of heart, and conscience of duty, out of which, by the operation of the Spirit, this assurance may, in due time, be revived; and by the which, in the meantime, they are supported from utter despair.” (18.4)

“This law, after his fall, continued to be a perfect rule of righteousness; and, as such, was delivered by God upon Mount Sinai, in ten commandments, and written in two tables: the first four commandments containing our duty towards God; and the other six, our duty to man.” (19.2)

"Although true believers be not under the law, as a covenant of works, to be thereby justified, or condemned; yet is it of great use to them, as well as to others; in that, as a rule of life informing them of the will of God, and their duty, it directs and binds them to walk accordingly…” (19.6)

“It is not to be made to any creature, but to God alone: and, that it may be accepted, it is to be made voluntarily, out of faith, and conscience of duty, in way of thankfulness for mercy received, or for the obtaining of what we want, whereby we more strictly bind ourselves to necessary duties; or, to other things, so far and so long as they may fitly conduce thereunto.” (22.6)

“No man may vow to do anything forbidden in the Word of God, or what would hinder any duty therein commanded, or which is not in his own power, and for the performance whereof he hath no promise of ability from God. In which respects, popish monastical vows of perpetual single life, professed poverty, and regular obedience, are so far from being degrees of higher perfection, that they are superstitious and sinful snares, in which no Christian may entangle himself.” (22.7)

“Civil magistrates may not assume to themselves the administration of the Word and sacraments; or the power of the keys of the kingdom of heaven; or, in the least, interfere in matters of faith. Yet, as nursing fathers, it is the duty of civil magistrates to protect the church of our common Lord, without giving the preference to any denomination of Christians above the rest, in such a manner that all ecclesiastical persons whatever shall enjoy the full, free, and unquestioned liberty of discharging every part of their sacred functions, without violence or danger. And, as Jesus Christ hath appointed a regular government and discipline in his church, no law of any commonwealth should interfere with, let, or hinder, the due exercise thereof, among the voluntary members of any denomination of Christians, according to their own profession and belief. It is the duty of civil magistrates to protect the person and good name of all their people, in such an effectual manner as that no person be suffered, either upon pretense of religion or of infidelity, to offer any indignity, violence, abuse, or injury to any other person whatsoever: and to take order, that all religious and ecclesiastical assemblies be held without molestation or disturbance.” (23.3)

“It is the duty of people to pray for magistrates, to honor their persons, to pay them tribute or other dues, to obey their lawful commands, and to be subject to their authority, for conscience' sake. Infidelity, or difference in religion, doth not make void the magistrates' just and legal authority, nor free the people from their due obedience to them: from which ecclesiastical persons are not exempted, much less hath the pope any power and jurisdiction over them in their dominions, or over any of their people; and, least of all, to deprive them of their dominions, or lives, if he shall judge them to be heretics, or upon any other pretense whatsoever.” (23.4)

“It is lawful for all sorts of people to marry, who are able with judgment to give their consent. Yet it is the duty of Christians to marry only in the Lord. And therefore such as profess the true reformed religion should not marry with infidels, papists, or other idolaters: neither should such as are godly be unequally yoked, by marrying with such as are notoriously wicked in their life, or maintain damnable heresies.” (24.3)

Similar language is used in the Three Forms of Unity, and of course, my own Confession—the 1689 London Confession of Faith. 

Perhaps the place where this language becomes most concrete is in relation to the Christian’s understanding of the function of the law in his/her life. Note what the WCF says, “The moral law doth forever bind all, as well justified persons as others, to the obedience thereof; and that, not only in regard of the matter contained in it, but also in respect of the authority of God the Creator, who gave it. Neither doth Christ, in the gospel, any way dissolve, but much strengthen this obligation.”

Notice that the obligation (i.e. the duty) of keeping the law is actually strengthened for the Christian—that is, now that they partake of the Holy Spirit and are in union with Christ, the obligation to keep the law becomes more pressing for them—specifically because they are now “slaves to righteousness” instead of to sin (Romans 6:18). Having been freed from the law’s curse, the law becomes to them the law of perfect liberty.