Believers in Jesus Christ should not lie to each other. Here is why:
Do not lie to each other, since you have taken off your old self with its practices and have put on the new self, which is being renewed in knowledge in the image of its Creator. (Colossians 3:9-10)
True believers must move forward in Christ. We have been set free from sin, therefore we should no longer behave as if we were still in bondage to it. We have put on a “new self” which has different characteristics than our “old self.” Indeed, our “old self” was a liar, constantly telling untruths. But our new self reflects God, the one who created us. This new self “is being renewed in knowledge and in the image of the Creator.” This means that true Christians are learning a lot and are changing to be more like God. Since God is truthful and does not lie we too ought to be truthful. We need to be living and preaching the truth. It is a contradiction to use lies to convince people to believe the truth.
So let us stop being deceitful one with another, and “speak the truth in love” (Ephesians 4:15).