1. God leads all things by His eternal law, often portrayed as Lady Wisdom in the Old Testament. See Ps. 19:7-10, 119; Prov. 3:13-25, 8:1-9:18; Sir. 1:1-18; Wis. 7:14-10:21. As St. Thomas Aquinas points out, the eternal law is the primordial principal upon which all other governance is based. See Summa Theologica II-I q. 93 art. 1.

    1. The moral law is God’s guidance that we may use our freedom well to participate in that eternal wisdom. “The moral law is the work of divine Wisdom. Its biblical meaning can be defined as fatherly instruction, God’s pedagogy. It prescribes for man the ways, the rules of conduct that lead to the promised beatitude; it proscribes the ways of evil which turn him away from God and His love. It is at once firm in its precepts, and in its promises, worthy of love Man participates in the wisdom and goodness of the Creator who gives Him

      mastery over his acts and the ability to govern himself with a view to the true and the good. .


      . . The natural law, present in the heart of each man and established by reason, is universal in its precepts and its authority extends to all men.” Catechism 1949, 1954, 1956. We can thus see the commandments of God as increasing our ability to be truly free, to participate in God’s creative goodness. See, e.g., John 8:31-32; James 1:25.

    2. Some principles (e.g., The Ten Commandments, the Beatitudes) are always and everywhere true by their nature. Other laws (e.g., the ritual laws of the ancient Jews or the liturgical laws of the Church) are still based upon the moral law, but can be changed according to circumstances. Civil laws likewise should be based upon the moral law, but can and should be changed according to circumstances if a different way of doing things (e.g., taxation, zoning, judicial proceedings) would now work better. Governments (whether ecclesial, political, economic or other) are thus good, so long, and only as long, as they uphold the moral law of God. As Jesus says, “Render unto Caesar what is Caesar’s, but render unto God what is God’s.” Matt 22:21; Mark 12:17; Luke 20:25. St. Paul likewise says that human authority is meant to be from God. See Rom. 13:1-7.

    3. There are some fundamental principles of human nature that are at the very heart of virtuous living and thus are the foundation of all other moral laws.

      1. The love of God and neighbor are at the heart of all good laws. When asked what the greatest commandment is, Jesus replied, “‘You shall love the Lord your God with all your heart, with all your soul, and with all your mind.’ This is the great and first commandments. And a second is like it, ‘You shall love your neighbor as yourself.’ On these two commandments depend all the law and the prophets.” Matt. 22:37-40. Likewise, St. John wrote, “He who does not love the brother whom he does see cannot love the God whom he does not see.” 1 John 4:20-21. Building on the love of neighbor, there is the principle that another person should never be used as an object, but rather looked at as an immortal and sacred person, beloved of God. See, e.g., Catechism 1931.

      2. Jesus gave enunciated basic principles in other sermons, most prominently in the Sermon on the Mount when He said such things as, “Seek first His kingdom and His righteousness, and all these things shall be yours as well,” and “Whatever you wish that men would do to you, d so to them; for this is the law and the prophets.”

      3. Another fundamental principle is that one should never commit an action that is inherently wrong so even for the purpose of making a good come from it. Matt. 5:19; Catechism 1753, 1756, 1761, 1789.

  2. The conscience is the testimony to this moral law that is in each person. One’s conscience is God’s ambassador in the soul. As such the conscience is compelling, but it can be an imperfect ambassador, for it can be in error.

    1. Each person has a conscience, a desire for truth and goodness. As St. Paul says, “When the Gentiles who do not have the law by nature observe the prescriptions of the law, they are a law unto themselves, even though they do not have the law. They show that the demands of the law are written in their heart.” Rom. 2:14. The Catechism describes this principle in more detail, saying, “Moral conscience, present at the heart of the person, enjoins him at the appropriate moment to do good and to avoid evil. It also judges particular choices, approving those that are good and denouncing those that are evil. It bears witness to the authority of truth in reference to the supreme God to which the human person is drawn, and it welcomes the commandments. When he listens to his conscience, the prudent man can hear God speaking.” Catechism 1777.

    2. As a result, one should always abide by one’s conscience, for it is our way of hearing God’s commands. And this obligation is the firmest foundation for individual dignity and political rights. For example, as the Vatican II Council’s document on religious liberty says, the obligation to pursue the truth and adhere to it once known is the basis for religious and intellectual freedom. See Dignitatis Humanae 2. This divine obligation is in fact the firmest grounding for the idea of human rights and dignity.

      - Unfortunately, people often speak about rights while ignoring this calling of conscience, which is its fundamental base. As Pope Emeritus Benedict XVI wrote in Caritas in Veritate (2009) section 43, people today are often “concerned only with their rights, and they often have great difficulty in taking responsibility for their own and other people's integral development. Hence it is important to call for a renewed reflection on how rights presuppose duties, if they are not to become mere license.

      Nowadays we are witnessing a grave inconsistency. On the one hand, appeals are made to alleged rights, arbitrary and non-essential in nature, accompanied by the demand that they be recognized and promoted by public structures, while, on the other hand, elementary and basic rights remain unacknowledged and are violated in much of the world.”

    3. However, conscience, as glorious as it is, can be in error. Like any other human skill, it must be developed, or it will fail altogether. “Conscience must be informed and moral judgment enlightened. . . . The education of the conscience is a lifelong task. . . In the formation of conscience the Word of God is the light for our path; we must assimilate it in faith and prayer and put it into practice. We must also examine our conscience before the Lord’s Cross. We are assisted by the gifts of the Holy Spirit, aided by the witness or advice of others and guided by the authoritative teaching of the Church.” Catechism 1783-1785.

    4. Because the human conscience is fallible and limited, God reveals things to us about the moral law both by Scripture and the Church.

      1. We certainly have a calling to develop our reason naturally by careful thinking,

        knowledge and consultations with other people. It is natural wisdom to understand that the development of a conscience is both essential and difficult.

      2. Precisely because it is not easy to develop our consciences, and because we can easily be in error, both individually and as a society, God also gives us revelation about what is true and false in human action as well as in external fact. See St. Thomas Aquinas, Summa Theologica II-I q. 91 art. 4.

      3. God revealed the beginnings of the law to the ancient Jews, in preparation for their completion in the preaching of Christ. “God, our Creator and Redeemer, chose Israel for Himself to be His people and revealed His Law to them, thus preparing for the coming of Christ The Old Law is the first stage of revealed Law. Its moral

        prescriptions are summed up in the Ten Commandments. The precepts of the Decalogue [the Ten Commandments] lay the foundation for the vocation of man fashioned in the image of God; they prohibit what is contrary to the love of God and neighbor and prescribe what is essential to it.” Catechism 1961 - 1962.

      4. Jesus Christ then built upon the ancient covenant by revealing a more advanced law (but one still consistent with the ancient law) that calls us to live out the highest aspirations of the human life. Thus, for example, we receive in the Gospels the Beatitudes, the gifts of the Holy Spirit and the striving to learn and live out the example or Jesus Christ and the saints through the love of God and neighbor. “The New Law, or the Law of the Gospel, is the perfection here on earth of the divine law, natural and revealed. The New Law is the grace of the Holy Spirit given to the

        faithful through faith in Christ. It works through charity; it uses the Sermon on the Mount to teach us what must be done and makes use of the sacraments to give us the grace to do it.” Catechism 1965, 1966

      5. Because the Scriptures do not answer all questions clearly (e.g., just war theory, when children should be baptized, and who should do so), and because new questions arise (e.g., over the role of government in a mercantile economy, genetic engineering and other bioethical matters), God also gave the Church the ability to hand down teachings on moral issues. Thus, “the Church, the pillar and bulwark of the truth, has received this solemn command of Christ from the apostles to announce the saving truth. To the Church belongs the right always and everywhere to announce moral principles, including those pertaining to the social order, and to make judgments on any human affairs to the extent that they are required by the fundamental rights of the human person or the salvation of souls.” Catechism 2032.

III Sin is contrary to the moral law and thus to the eternal law of God. It is “an offense against reason, truth, and right conscience; it is a failure in genuine love for God and neighbor caused by a perverse attachment to certain goods. It wounds the nature of man and injures human solidarity.” Catechism 1849.

  1. Most personal sins are venial, which means they weaken, but not destroy the friendship with God. However, some sins are mortal, which means that they will destroy our friendship with God if unrepented. Thus, St. John speaks of sins that are mortal and sins that are lesser. 1 John 5:16-17. And St. Paul lists some sins that prevent one from

    inheriting the kingdom of heaven. See Gal. 5:19-21. Such sins require repentance in order for the relationship with God to be restored; and the ordinary means of such repentance in the Catholic Church involves the sacrament of Reconciliation. See Catechism 1484.

    - “The distinction between mortal and venial sin, already evident in Scripture, became part of the tradition of the Church. Mortal sin destroys charity in the heart of man by a grave violation of God’s law; it turns man away from God, who is his ultimate end and his beatitude Mortal sin is sin whose object is a grave

    matter and which is also committed with full knowledge and deliberate consent.” Catechism 1854, 1855, 1857.

  2. “The movement of return to God, called conversion and repentance, entails sorrow for and abhorrence of sins committed, and the firm purpose of sinning no more in the future. Conversion touches the past and the future and is nourished by hope in God’s mercy.” Catechism 1490.

  3. Repentance from sins involves a sorrow at sin, but also a rejoicing at the cleansing God offers and the triumph of grace. As Pope Francis recently wrote, “How good it feels to come back to Him whenever we are lost! With a tenderness that never disappoints, but is always capable of restoring our joy, He makes it possible for us to lift our heads and start anew.” Pope Francis, Apostolic Exhortation The Joy of the Gospel (2013) 3.

  1. Overcoming sin and achieving the holiness that we are all called to requires the grace of God and our own cooperation.

    1. We cannot achieve this holiness on our own. Even without the Fall, grace would have been needed to achieve the holiness that exceeds natural human capacity. With the Fall, that grace is needed all the more. As St. Paul says, “The willing is at hand, but the good is not. For I do not do the good I want, but the evil that I do not want. . .

      . So then I discover the principle that when I want to do the right evil is at hand.” Rom. 7:18-19, 21. We need God’s grace continually to overcome those struggles.

    2. But God does give us that grace, not simply as forgiveness or a pardon of sins, but as a real change within that makes us grow as children of God. As St. Pope John Paul II said, “Following Christ is not an outward imitation, since it touches man at the very depths of his being Christ dwells by faith in the heart of the believer, and then

      the disciple is conformed to the Lord. This is the effect of grace, of the active presence of the Holy Spirit within us.” Veritatis Splendor (1993) 21. It makes us coheirs with Christ and members of the household of God united throughout time and space. See Eph. 2:1-22

    3. Grace is thus, not just an outward declaration of pardon, but a sanctification, a sharing in the life of Christ and therefore in the life of God. See Catechism 1996-99. It allows us to advance towards holiness and eventually to arrive at the state of perfect sanctity and purity, which is needed for us to enter into heavenly glory. See Rev. 21:26-27.

    4. However, even though we do not earn grace by our deeds, we must still act in accord with grace in order for it to have an effect. As St. Paul says, “Work out your salvation with fear and trembling. For it is God is the One, who for His good purpose, who works in you, both to desire and to word.” See Phil 2:12.

      1. Thus, “the way of perfection passes by way of the Cross. There is no holiness without renunciation and spiritual battle. Spiritual progress entails the ascesis and mortification that gradually lead to living in the peace and joy of the Beatitudes.” Catechism 2015. As Jesus says, “Whoever wishes to come after Me must deny himself, take up his cross and follow me.” Mark 8:34; see also Matt. 10:38-39; Luke 14:26-27.

      2. But this very calling makes our own struggles a partnership with Christ. As the Catechism declares, “By His passion and death on the cross Christ has given a new meaning to suffering: it can henceforth configure us the Him and unite us with His redemptive passion . . . Christ invites His disciples to follow Him by taking us their cross in turn.” Catechism 1505-1506. “In time we can discover that God in His almighty providence can bring a good from the consequences of and evil, even a moral evil, caused by His creatures From the greatest moral

evil ever committed - the rejection and murder of God’s only Son, caused by the sins of all men - God, by His grace that abounded all the more, brought the greatest of goods: the glorification of Christ and our redemption.” Catechism

312. Thus, as St. Paul says, the suffering of this age “is preparing for us an eternal weight of glory beyond all comparison.” Eph. 4:17.