This phrase is often used to emphasize the importance of being honest and truthful in all aspects of life. Honesty is a virtue that is essential for building trust and strong relationships with others. It is also important for maintaining personal integrity and self-respect. Honesty is the best policy because it
From Wikipedia
Honesty or truthfulness is a facet of moral character that connotes positive and virtuous attributes such as integrity, truthfulness, straightforwardness, along with the absence of lying, cheating, theft, etc. Honesty also involves being trustworthy, loyal, fair, and sincere.