In the description of some listening devices for music, we may have seen the letters “hi-fi.” High fidelity is a guarantee that the sound reproduced is as close as possible to the original source. Fidelity is understood here as accuracy, as the ability to preserve something as perfectly intact as possible. But in the culture of the ancient Middle East, where God’s revelation to the people of Israel took place, the concept of fidelity has a somewhat different connotation. Fidelity is not associated with precision. Rather the emphasis is placed on other aspects such as stability and permanence over time – on reliability, loyalty and truthfulness. Moreover, in biblical language fidelity is also closely linked to God’s fatherly mercy, for which the concept of exactness doesn’t seem well suited.
Not like other gods
If we look in Sacred Scripture for a full definition of faithfulness, we will fail to find it. But if we read the sacred books asking ourselves who is faithful, both the Old and the New Testaments give us a clear answer: God is faithful (cf. Deut 32:4; 1 Cor 1:9; 1 Thess 5:24 and others). What does it mean to say that God is faithful? Why is faithfulness so often highlighted as a quality possessed by the Lord?
For one thing, the God of Israel’s faithfulness is in contrast to the gods of neighboring peoples. “God is the foundation of hope: not any god.” Pagan myths show us gods who behave in fickle and capricious ways; sometimes they are good, and sometimes bad; one never knows how they are going to react. Therefore it is not reasonable to trust them. In Egypt and Mesopotamia, for example, it was common to represent the gods in the form of a bull, lion, eagle, dragon, or other animals. As a result, the cult of these divinities was steeped in attitudes that are similar to how we would react to a threatening beast: satisfy its hunger, appease its anger, or simply not interrupt its rest.
This is not the case in Israel. The Mosaic law prohibits representing the Lord with figures of any kind (cf. Ex 20:4; Lev 19:4). The God of Israel accepts sacrifices and offerings, but not because he is in need or somehow depends on them (cf. Ps 50:7-15; Dan 14:1-27). That the Lord is faithful, in contrast to false gods, means that he is not capricious or inconstant, that we can intuit in some way how he is going to act. At the same time, this fidelity does not imply that God follows a uniform pattern of conduct or that his way of intervening in history is repetitive. God is free, transcendent and sovereign. “He is all motion, all beauty, all greatness.” Therefore his fidelity to the covenant does not exclude novelty (cf. Is 43:16-19). Through the mouth of the prophet Isaiah the Lord tells us: For my thoughts are not your thoughts, neither are your ways my ways, says the Lord. For as the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts (Is 55:8-9). God always saves his people, but not always in the same way. “With this newness he is always able to renew our lives and our communities, and even if the Christian message has known periods of darkness and ecclesial weakness, it will never grow old.”
Besides this difference, a frequent deviation from a right relationship with God is trying to control Him or use Him at our discretion. Therefore divination and other similar practices were severely prohibited in Israel (cf. Lev 19:26.31). That God is faithful to his word does not mean that his way of behaving is always identical, and therefore predictable and controllable by us. We can be sure that He will never stop loving us, although often we don’t know how. His logic always exceeds ours. Sometimes He can give us more than what He promised, or fulfill a prophecy in an unexpected way. “Fidelity has nothing sterile or static; it is creative.”
A God “abounding in steadfast love and faithfulness”
The Bible testifies that the Lord is faithful in contrast to the false gods of neighboring peoples; although in reality, the sacred text affirms this above all in contrast to human beings: The Glory of Israel will not lie or repent; for he is not a man, that he should repent (1 Sam 15:29). Unlike our human experience, the Lord always tells the truth. He does not go back on his promises: God is not man, that he should lie, or a son of Adam, that he should repent. Has he said, and will he not do it? Or has he spoken, and will he not fulfil it? (Num 23:19). Only God is absolutely steadfast and reliable. We can build our life on Him with the certainty of never being disappointed. As Benedict XVI said: “While everything else passes and changes, the Word of the Lord is not transient. If the events of life make us feel bewildered and every certainty seems to crumble, we have a compass to guide us; we have an anchor to prevent us from drifting away.”
The book of Exodus tells that, after they sinned by worshipping the golden calf, God renewed the covenant with his people on Mount Sinai. Then, before giving Moses the tablets of the law for the second time, the Lord passed before him saying: The Lord, the Lord, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness (Ex 34:6). These words are usually seen as a second revelation of God’s name, after the previous revelation, also to Moses. This description of what God is like is found repeated, with slight variations, in seven other passages from various books of the Old Testament. Saint Josemaría said: “If you go through the Holy Scriptures, you will discover constant references to the mercy of God . . . What security should be ours in considering the mercy of the Lord!”
Nevertheless, Israel knows that their Lord is compassionate and faithful not simply because of what he told Moses on Sinai, but above all because the people have experienced it in their own history, in their own flesh. God has manifested his faithfulness not simply by declaring it, but by showing it in his works. Israel experiences the salvation brought about by God’s faithfulness throughout its history. O Lord, thou art my God; I will exalt thee, I will praise thy name; for thou hast done wonderful things, plans formed of old, faithful and sure (Is 25:1). God’s works show his faithfulness; Israel is a witness, time and time again, that his mercy does not vanish in the face of human infidelity. The Lord is good; his steadfast love endures forever, and his faithfulness to all generations (Ps 100:5), sings the psalmist. And in another passage: I will sing of your mercy forever, Lord, and proclaim your faithfulness through all ages (Ps 89:2).
We see Mary, in the Magnificat, praising this way of being of God, so clear for those familiar with sacred history. The mother of Jesus praises God for having deigned to recognize her low estate, and for working great things in her, in remembrance of his mercy, as he spoke to our fathers, to Abraham and to his posterity forever (Lk 1:54-55). Saint John Paul II said that “in the Magnificat, a truly theological canticle because it reveals Mary’s experience of God’s face, God is not only the Powerful, for whom nothing is impossible, as Gabriel had declared (cf. Lk 1:37), but also the Merciful, capable of tenderness and faithfulness towards every human being.”
Jesus is the fulfillment of the promises
Fidelity is an attribute that defines God’s relationship with mankind, especially with his people by virtue of the covenant. And to describe the strength of this covenant, the prophets make use of several images. One of these is marriage, which we find developed above all in the books of Hosea, Jeremiah and Ezekiel. This image highlights the mercy of the Lord, who is willing to forgive and restore the covenant despite Israel’s repeated infidelities. Another image is that of fatherhood and motherhood. The book of Isaiah uses it several times to stress in a moving way how God will never abandon his people: But Zion said: “The Lord has forsaken me, my Lord has forgotten me.” Can a woman forget her nursing child, that she should have no compassion on the child of her womb? Even these may forget, yet I will not forget you. Behold, I have engraved you on the palms of my hands (Is 49:14-16).
Jesus represents in his person the whole legacy of fidelity and mercy found in the Old Testament, and reveals the continuation of that divine work. His compassion for the crowds leads our Lord to echo Isaiah’s words insisting that God will never forget us: O Jerusalem, Jerusalem, killing the prophets and stoning those who are sent to you! How often would I have gathered your children together as a hen gathers her brood under her wings, and you would not! (Mt 23:37). Jesus is deeply hurt by the rebellion of men, by their hardness of heart in the face of the insistence – the fidelity – of God’s love.
Inspired by another passage from the prophet Isaiah that describes Israel as the vineyard of the Lord (cf. Is 5:7), Jesus summarizes the history of God’s fidelity in the face of human infidelity by recounting the parable of the murderous vinedressers (cf. Mk 12:1-12). After sending successive servants to claim the fruit of his vineyard, all of whom meet with rejection, the owner of the vineyard decides to send as a last resort his son. But the vinedressers kill him. The coming of Jesus, the only Son of God, and his death on the Cross is the full manifestation of the God of Israel’s faithfulness and mercy. After sending his Son to die for us, God can do nothing greater (cf. Heb 1:1-2).
The apostles in their preaching were aware of the close tie between the Paschal Mystery of Christ – his passion, death and resurrection – and God’s fidelity to his ancient promises. Jesus is the Amen, the faithful and true witness (Rev 3:14), the book of Revelation tells us. In Saint Paul’s second letter to the Corinthians, we find the most explicit statement in this regard: As surely as God is faithful, our word to you has not been Yes and No. For the Son of God, Jesus Christ, whom we preached among you, Silvanus and Timothy and I, was not Yes and No; but in him it is always Yes. For all the promises of God find their Yes in him (2 Cor 1:18-20). This conviction has become part of the faith of the Church, which has constantly proclaimed that Jesus is the faithful fulfillment of all that God had promised (cf. 1 Cor 15:3-4).
If we are not faithful, he remains faithful
Referring to those who refused to believe in Christ during his lifetime here on earth, Saint Paul points to God’s exceeding greatness: What if some were unfaithful? Does their faithlessness nullify the faithfulness of God? By no means! (Rom 3:3-4). We can safely put all our trust in God. Some boast of chariots, and some of horses; but we boast of the name of the Lord our God (Ps 20:7), says the psalmist, expressing his confidence in the Lord above human strategies for battle. For who is God, but the Lord? And who is a rock, except our God? (2 Sam 22:32), Sacred Scripture says, in the Hymn of David. Only God can be called the Rock on which we can lean without fear for protection. The use of the term “Rock” for God is so frequent in the Old Testament that sometimes the sacred text simply says “the Rock” without needing to say who it refers to.
In insisting on God’s fidelity, often in contrast to the infidelity of men, Sacred Scripture doesn’t seem to place much confidence in human faithfulness. But more than a pessimistic view of human strength, it is a realistic and profound affirmation of our smallness in the face of his power. That is how this harsh oracle transmitted by Jeremiah can best be understood: Thus says the Lord: “Cursed is the man who trusts in man and makes flesh his arm, whose heart turns away from the Lord. He is like a shrub in the desert, and shall not see any good come. He shall dwell in the parched places of the wilderness, in an uninhabited salt land. Blessed is the man who trusts in the Lord, whose trust is the Lord. He is like a tree planted by water, that sends out its roots by the stream, and does not fear when heat comes, for its leaves remain green, and is not anxious in the year of drought, for it does not cease to bear fruit” (Jer 17:5-8).
The important point here is that we human beings cannot be faithful in the same way that God is faithful. Our human response to God’s fidelity is not impeccable conduct without any fissures, but rather faith (cf. Gen 15:6; Heb 11:1). In fact, the Hebrew language uses the same word to say that God is faithful and to describe someone who believes in Him. The New Testament calls those who believe in Christ and follow Him “faithful” (cf. Acts 10:45). What God wants from us is not that we be as firm and solid as He is, which would be impossible. Rather He wants us to place all our trust in Him, as Mary did and as the saints have done, for he who promised is faithful (Heb 10:23). And, above all, He wants us to acknowledge our offenses and ask for forgiveness. If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just, and will forgive our sins and cleanse us from all unrighteousness (1 Jn 1:8-9). Although we are sinners, God never abandons us. If we are unfaithful he remains faithful, for he cannot deny himself (2 Tim 2:13).
“Our fidelity is simply a response to God’s fidelity. God who is faithful to his word, who is faithful to his promise.” As the Prelate of Opus Dei said: “Faith in God’s faithfulness gives strength to our hope, even though our personal weakness sometimes leads us not to be entirely faithful, in small things or perhaps, on occasion, in big things. Then fidelity consists in following, with God’s grace, the path of the prodigal son.” The important thing is to always return to the One who keeps his promises, to return with faith to the Rock who is always waiting for us.
 Benedict XVI, Enc. Spe salvi, no. 31.
 Saint Josemaría, Friends of God, no. 190.
 Francis, Apost. Exhort. Evangelii Gaudium, no. 11.
 Benedict XVI, Homily, 12 September 2009.
 Benedict XVI, Angelus, 12 December 2010.
 Cf. Num 14:17-18; Deut 7:9-10; Ps 86:15; 145:8; Joel 2:13; Jon 4:2 and Nah 1:3.
 Saint Josemaría, Christ Is Passing By, no. 7.
 Saint John Paul II, Audience, 6 November 1996.
 Cf. for example Deut 32:4; 1 Sam 2:2; 2 Sam 22:2; Ps 19:15; 28:1; 71:3; Is 17:10; Hab 1:12 and others.
 Francis, Homily, 15 April 2020.
 Fernando Ocáriz, Pastoral Letter, 19 March 2022.