by Wayne Grudem
Truthfulness (and Faithfulness). God’s truthfulness means that he is the true God, and that all his knowledge and words are both true and the final standard of truth.
The term veracity, which means “truthfulness” or “reliability,” has sometimes been used as a synonym for God’s truthfulness.
The first part of this definition indicates that the God revealed in Scripture is the true or real God and that all other so-called gods are idols. “The LORD is the true God; he is the living God and the everlasting King. . . . The gods who did not make the heavens and the earth shall perish from the earth and from under the heavens” (Jer. 10:10–11). Jesus says to his Father, “And this is eternal life, that they know you the only true God, and Jesus Christ whom you have sent” (John 17:3; cf. 1 John 5:20).
We might ask what it means to be the true God as opposed to other beings who are not God. It must mean that God in his own being or character is the one who fully conforms to the idea of what God should be: namely, a being who is infinitely perfect in power, in wisdom, in goodness, in lordship over time and space, and so forth. But we may further ask, whose idea of God is this? What idea of God must one conform to in order to be the true God?
At this point our train of thought becomes somewhat circular, for we must not say that a being must conform to our idea of what God should be like in order to be the true God! We are mere creatures! We cannot define what the true God must be like! So we must say that it is God himself who has the only perfect idea of what the true God should be like. And he himself is the true God because in his being and character he perfectly conforms to his own idea of what the true God should be. In addition, he has implanted in our minds a reflection of his own idea of what the true God must be, and this enables us to recognize him as God.
The definition given above also affirms that all of God’s knowledge is true and is the final standard of truth. Job tells us that God is “perfect in knowledge” (Job 37:16; see also the verses cited above under the discussion of God’s omniscience). To say that God knows all things and that his knowledge is perfect is to say that he is never mistaken in his perception or understanding of the world: all that he knows and thinks is true and is a correct understanding of the nature of reality. In fact, since God knows all things infinitely well, we can say that the standard of true knowledge is conformity to God’s knowledge. If we think the same thing God thinks about anything in the universe, we are thinking truthfully about it.
Our definition also affirms that God’s words are both true and the final standard of truth. This means that God is reliable and faithful in his words. With respect to his promises, God always does what he promises to do, and we can depend on him never to be unfaithful to his promises. Thus, he is “a God of faithfulness” (Deut. 32:4). In fact, this specific aspect of God’s truthfulness is sometimes viewed as a distinct attribute: God’s faithfulness means that God will always do what he has said and fulfill what he has promised (Num. 23:19; cf. 2 Sam. 7:28; Ps. 141:6; et al.). He can be relied upon, and he will never prove unfaithful to those who trust what he has said. Indeed, the essence of true faith is taking God at his word and relying on him to do as he has promised.
In addition to the fact that God is faithful to his promises, we must also affirm that all of God’s words about himself and about his creation completely correspond to reality. That is, God always speaks truth when he speaks. He is “the unlying God” (Titus 1:2, author’s translation), the God for whom it is impossible to lie (Heb. 6:18), the God whose every word is perfectly “pure” (Ps. 12:6), the one of whom it can be said, “Every word of God proves true” (Prov. 30:5). God’s words are not simply true in the sense that they conform to some standard of truthfulness outside of God. Rather, they are truth itself; they are the final standard and definition of truth. So Jesus can say to the Father, “Your word is truth” (John 17:17). What was said about the truthfulness of God’s knowledge can also be said about God’s words, for they are based on his perfect knowledge and accurately reflect that perfect knowledge: God’s words are “truth” in the sense that they are the final standard by which truthfulness is to be judged: whatever conforms to God’s own words is also true, and what fails to conform to his words is not true.
The truthfulness of God is also communicable in that we can in part imitate it by striving to have true knowledge about God and about his world. In fact, as we begin to think true thoughts about God and creation, thoughts that we learn from Scripture and from allowing Scripture to guide us in our observation and interpretation of the natural world, we begin to think God’s own thoughts after him! We can exclaim with the psalmist, “How precious to me are your thoughts, O God! How vast is the sum of them!” (Ps. 139:17).
This realization should encourage us in the pursuit of knowledge in all areas of the natural and social sciences and the humanities. Whatever the area of our investigation, when we discover more truth about the nature of reality, we discover more of the truth that God already knows. In this sense we can affirm that “all truth is God’s truth”7 and rejoice whenever the learning or discovery of this truth is used in ways pleasing to God. Growth in knowledge is part of the process of becoming more like God or becoming creatures who are more fully in God’s image. Paul tells us that we have put on the “new nature,” which, he says, “is being renewed in knowledge after the image of its creator” (Col. 3:10).
In a society that is exceedingly careless with the truthfulness of spoken words, we as God’s children are to imitate our Creator and take great care to be sure that our words are always truthful. “Do not lie to one another, seeing that you have put off the old nature with its practices and have put on the new nature” (Col. 3:9–10). Again Paul admonishes, “Therefore, putting away falsehood, let every one speak the truth with his neighbor” (Eph. 4:25). In his own ministry, Paul says that he sought to practice absolute truthfulness: “We have renounced disgraceful, underhanded ways; we refuse to practice cunning or to tamper with God’s word, but by the open statement of the truth we would commend ourselves to every man’s conscience in the sight of God” (2 Cor. 4:2). God is pleased when his people put “devious talk” far from them (Prov. 4:24) and speak with words that are acceptable not only in the sight of people but also in the sight of the Lord himself (Ps. 19:14).
Furthermore, we should imitate God’s truthfulness in our own reaction to truth and falsehood. Like God, we should love truth and hate falsehood. The commandment not to bear false witness against our neighbor (Ex. 20:16), like the other commandments, requires not merely outward conformity but also conformity in heart attitude. One who is pleasing to God “speaks truth from his heart” (Ps. 15:2), and strives to be like the righteous man who “hates falsehood” (Prov. 13:5). God commands his people through Zechariah, “Do not devise evil in your hearts against one another, and love no false oath, for all these things I hate, says the LORD” (Zech. 8:17).
These commands are given because God himself loves truth and hates falsehood: “Lying lips are an abomination to the LORD, but those who act faithfully are his delight” (Prov. 12:22; cf. Isa. 59:3–4). Falsehood and lying come not from God but from Satan, who delights in falsehood: “When he lies, he speaks according to his own nature, for he is a liar and the father of lies” (John 8:44). It is appropriate then that with “the cowardly, the faithless, the polluted” and the “murderers, fornicators, sorcerers, [and] idolaters” who are found in “the lake that burns with fire and sulphur” far from the heavenly city, are found also “all liars” (Rev. 21:8).
Thus, Scripture teaches us that lying is wrong not only because of the great harm that comes from it (and much more harm comes from lying than we often realize), but also for an even deeper and more profound reason: when we lie we dishonor God and diminish his glory, for we, as those created in God’s image and created for the purpose of reflecting God’s glory in our lives, are acting in a way that is contrary to God’s own character.
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From Wayne Grudem, Systematic Theology