The Ninth Commandment calls you to love and speak the truth, both in judicial settings and in the rest of life. Paul reflects that in Ephesians 4:25–32.
Do not lie. Do justice. God’s law outlines basic principles of justice: judges and public trials were established, Deuteronomy 16:18. Justice was not to be swayed by outside considerations, Exodus 23:1–9. The duty of witnesses was important. There were to be a plurality of witnesses, Deuteronomy 17:6; 19:15, and they were to be participants in the judgment, Deuteronomy 17:7. Maliciously false witnesses were to be punished, Deuteronomy 19:16–21. True witness is impossible without the fear of God. Nothing but the truth must be spoken in testimony. Justice needs God’s law, 2 Chronicles 19:6,7. In an age when the name of God has become an expletive, is it any wonder that the truthfulness, even of sworn testimony, is often in doubt?
“[S]lander is often praised under the pretext of zeal and conscientiousness. Hence it happens that this vice insinuates itself even among the saints, creeping in under the name of virtue.”
John Calvin, Commentary on the Pentateuch, at Exodus 20:16
Love God’s truth in all your life. As God’s people, speak the truth, Ephesians 4:15. Reflect his truthfulness. A Christian’s “yes” should really mean that! Truth-speaking is crucial to growing up into Christ. A functioning society is impossible without truth. Call those around you to the truth. God requires truth in all your relationships. Gossip is forbidden, as is slander, Leviticus 19:16; Proverbs 11:13; Romans 1:29. Go to your brother, instead of speaking to others, Matthew 18:15–17; 5:23, 24. God takes lying seriously, Revelation 22:15. Included are “little white lies.” Social media provides a platform where it is very easy to spread either falsehood or accusations that we have not verified. Children, what do you do when you’ve done something wrong and you mother asks you, “Did you do that?” or “Did you break this?” Instead of lying, remember that God expects you to speak the truth. Adults, examine what comes out of your mouth. Ask yourself, before you speak, whether what you are about to say will build up or tear down, Ephesians 4:29. Notice how the warning against grieving the Spirit is bracketed by admonitions about the tongue. Yet there are some who have no right to the truth, for example Samuel’s stated reason for visiting Bethlehem, 1 Samuel 16:2. There are times to be justly silent. False prophecy is an especially serious violation, punishable by death in the Old Testament, Deuteronomy 18:20. Many churches today are guilty of this sin–false teaching, denial of the resurrection, etc.
In contrast to the false prophets is the Prophet. Be a true witness. Your Lord and the Spirit are witnesses. Jesus is full of grace and truth, John 1:14. He is the fullness of the Old Testament shadows. He is the truth, John 14:6, the only way to God. The truth is identified with Jesus Christ. Christ is the Savior in his prophetic office, not only as priest. He is the Prophet of Deuteronomy 18:18. Peter identifies Jesus Christ as the fulfillment of this prophecy, Acts 3:22, 23. John calls Jesus “the Word,” John 1:1. The author of Hebrews reminds you that God has spoken, finally and definitively, in his Son, Hebrews 1:1, 2. He is the faithful and true witness, Revelation 3:14 (and 1:5). You cannot come to the Father without listening to Jesus Christ, without receiving him as the full revelation of God. Christ’s mission was one of truth, John 18:37, 38. His Spirit of truth is in you, his people. The function of the promised Spirit was that of a witness, John 16:7–15. It is explicitly the coming of the Spirit that equips the disciples to be witnesses, Acts 1:8, unfolded throughout the book of Acts. The same Spirit inspired the Scriptures, which serve as a witness to God, Acts 10:42–43.
Be the witness that you are. Telling the truth is not just a matter of guarding your tongue. It involves trust in the one who is the Truth. It involves being filled by the Spirit who enables you to be a witness. You see that in Acts, as the Spirit-filled church continues to do the work of the risen, exalted, ascended Lord. That work certainly included “witnessing” in the way that the term is used in religious circles. But it was broader. It included a life, a way of living that drew questions, that pointed people to the Savior. They, and you, are called to live as transformed people.
“We should keep in mind that Paul is dealing with very few educated and political elites in the congregations he founded (e.g. 1 Cor 1:26). The Ephesian audience no doubt contained at least partly a pretty rough crowd, and the Gentile contingent may have been unversed in OT wisdom literature and its plethora of statements on the moth, the tongue, or the words of the wise and the fool. They may have been surprised to learn that even the way they talk had to be reformed on conversion to Christ. But here we see the unity of the congregation and its mutual growth and edification is paramount in Paul’s mind (4:15–16; cf. v. 32; Rom 14:19). Furthermore, it does not take a call to the special offices of he church (4:11) to be able to ‘give grace to those who hear’ with one’s words; this is an obligatory privilege of all Christians as well.”
S. M. Baugh, Ephesians, pages 396–397
Be ready to speak. But do more than just talk about yourself and what you have experienced. Our culture is quite ready to grant that people have interesting and unusual experiences—and so what? Use the witness of Scripture as you speak. Depend on the Spirit, who promised to enable you to speak. Witness is something corporate as well. The church gathered in worship, is a witness to the world, 1 Corinthians 14:24–25. That means that how you worship is important. Being present in worship is part of the testimony of Christ to the perishing world.
By nature we belonged to the one who is the father of lies. But, thank God, his Son has come as the Truth, not only calling you to speak truthfully, but by giving his life to pay for your sin of lying and by working in you a love for the truth. Speak the truth in Christ!