16 “You shall not give false testimony against your neighbor.” (Exodus 20:16)
Simply put, do not lie.
It always catches up with you at some point and there are always negative consequences that come along with it. God wants us to avoid those consequences (or at least the most severe versions of those consequences) by telling the truth.
This is not to say that we should tell people exactly what we think about them all the time, because a lot of the time, the things we think about people are not encouraging. Having them know about these things every time is no good.
If you’re put in a position where you feel you have to lie to get out of something, just remember, it will catch up with you, and the consequences will be much more severe than if you just tell the truth in the first place. Lies can wreck families and marriages. You don’t want that.
For those of you who get really picky and say “God said to only not lie to my neighbour!”
In Luke 10 Jesus takes the concept of neighbour much further than just the person who lives next door to you. You neighbour is really anyone you talk to or run into in your day to day lives. Your wife is also your neighbour. So you best not lie to her especially.
In short, just don’t lie to anyone.