The Torah tells us in Parsha Mishpatim, that we are to "Distance yourself from falsehood." (Ex. 23:7) No other transgression, said Rabbi Simcha Bunim of Przysucha, has this commandment. What it is about falsehood that God is so concerned about us falling into?
There is the obvious problems that lying can get one in trouble. Each lie because bigger and bigger, and then you have to create new lies to cover up the other lies. Before you know it, you have constructed a life of lies.
But lying, we learn from several places in the Talmud, is at times permitted - especially to save a life and to prevent various levels of embarrassment. So if lying is permitted in those cases, what is the Torah referring to here?
The majority of our sages teach us that Torah is giving specific advice to judges. As Rav Hirsch wrote, "It makes it the judge's duty to meticulously avoid any and every thing by which there is the slightest possibility of the veracity of the judgement being affected."
I want to add another layer onto this. The Torah is also telling us to distance ourselves from lying to ourselves, and specifically from lying in how we judge ourselves.
So much personal strife results when we are are not honest with ourselves, who we are and what we are doing. We can end up judging ourselves very harshly, and distancing ourselves from God. Or we can fail to judge our actions and think that we are always right, and it's the other person who is in the wrong.
We must therefore keep ourselves far, far away from falsehood - from mock piety and self-importance, to self-defeating low self-esteem and not seeing all the wonderful and unique qualities that God gave to us.
Instead we need to judged ourselves and each other favorably, gently, and honestly. Then we will be acting with Godliness in our thoughts and actions, improve our performance of the mitzvot, and deepen our relationship with our friends, loved ones, and with God.