Dishonesty is not one of the Seven Deadly Sins.
Nor is it forbidden in the Decalogue. Now “Thou shalt not bear false witness against thy neighbor” is traditionally interpreted as forbidding lying, but that requires a skooch. There’s no nice and direct “Thou shalt not lie.”
The reason it bugs me is that, once you’ve noticed it, it seems almost premeditated. Deliberately leaving a loophole. Like the codifiers were nervous about cutting off too completely the option of deceit.
I used to think Pride was the root of all sins, since it requires putting one’s own wants before all other things. I guess that from a psychological viewpoint, one could still make a case for that, but it ignores that fact that some great sinners have been very humble people, thinking all for their causes and never for themselves. In practice, lying is often the first sin. The addict who says they don’t know where that wallet went. The spouse who neglects to say just how much time they’ve been spending with the co-worker. Lies provide a cover for other sins to grow, until such time as those sins are too large to conceal, and the initial lie can be discarded like a husk.
Where condemnation of lying really sticks out is in Revelation. I don’t know what happened to John of Patmos, but he makes sure to stress that “and all liars” are among the eternally damned. I think somebody hurt him bad once, lied and broke his heart. That’s what lies do.
Regardless of what might be down on paper, God sees our lies and the hurt they cause, and He remembers.