Imagine you're the manager in charge of hiring/firing at your company. You hire an employee and they do an excellent job. Several years later, you discover that they lied on their application to get the job. Assuming the lie is something that doesn't affect their ability to do their current job, would you fire them?
Some examples: 1. They lied about being previously fired from another job for attendance-related issues. (They haven't had any attendance issues with your company.) 2. They lied about being convicted of a DUI. (Their job does not involve driving at all.) 3. They made up a degree. (The degree has no bearing on their current occupation.)