You shall not bear false witness against your neighbour

The sermon was on the ninth commandment: “You shall not bear false witness against your neighbour.” The power of the words of a person who bears witness against his neighbour is sobering. If two or three witnesses could say with confidence that another person was guilty of murder, then their words would have him put to death, and they would cast the first stones in the execution. If these witnesses are found to be false then they would receive whatever punishment they were seeking for the person they were accusing. Witnessing and especially witnessing falsely was a life or death matter.
The Bible says much about the power of our words. Perhaps the paramount passage in the tongue is James 3:1-10 “Not many of you should become teachers, my brothers, for you know that we who teach will be judged with greater strictness. For we all stumble in many ways. And if anyone does not stumble in what he says, he is a perfect man, able also to bridle his whole body. If we put bits into the mouths of horses so that they obey us, we guide their whole bodies as well. Look at the ships also: though they are so large and are driven by strong winds, they are guided by a very small rudder wherever the will of the pilot directs. So also the tongue is a small member, yet it boasts of great things. How great a forest is set ablaze by such a small fire! And the tongue is a fire, a world of unrighteousness. The tongue is set among our members, staining the whole body, setting on fire the entire course of life, and set on fire by hell. For every kind of beast and bird, of reptile and sea creature, can be tamed and has been tamed by mankind, but no human being can tame the tongue. It is a restless evil, full of deadly poison. With it we bless our Lord and Father, and with it we curse people who are made in the likeness of God. From the same mouth come blessing and cursing. My brothers, these things ought not to be so.”
Why does God want us to tell the truth? Is it just because He wants society to function well? Or is there a deeper reason? Consider Col 3:9-10 “Do not lie to one another, seeing that you have put off the old self with its practices and have put on the new self, which is being renewed in knowledge after the image of its Creator.”
It would seem that for Paul a major reason for not lying is that we have been made new and are being renewed in the image of our Creator. He is the one who holds perfect knowledge and is truthful in all that He is. So to tell the truth is in fact part of being like God and being renewed in His image. We can also say that telling the truth is part of being truly human and being renewed in our humanity, since being in the image of God is what it means to be truly human.
Why do we lie and how do we stop? It would seem the reason we lie, more often than not, is to protect our reputations and make others think better of us than they ought. To overcome this we need to exchange man’s false opinions of us, that are often based on lies we’ve told, for God’s true opinion of us that He declares over us in Jesus Christ. We need to hear a true word of absolute acceptance from God, that our sins are forgiven and cast into the sea, for there we have no need to lie about them anymore. It is the truth of the gospel that we need to overcome lying, and it is the truth of the gospel that the world needs to be saved from death and given life in the truth.