That quote means that the truth is objective and doesn't depend on people's opinions or beliefs. Even if no one believes the truth, it remains true. On the other hand, a lie is something that is false, regardless of how many people believe it.
It's important to remember that the truth is always the most important thing. When we are honest with ourselves and others, we create a sense of trust and respect. Even if the truth is difficult or uncomfortable, it's still better than a lie.
Lies, on the other hand, can be very damaging. When we lie to others, we break down trust and create a sense of disconnection. Even if everyone believes a lie, it doesn't make it true. Ultimately, the truth will always come out, and it's better to be honest from the beginning.