Humans are taught from a young age not to deceive others. However, to be more precise, you should not deceive others, but you should not be deceived by others either. This is because if you are deceived, grudge will arise within you.
If we see or hear information that we do not know, we must first doubt the information and later find a way to verify the information to confirm its authenticity.
However, the real problem lies not with the method of verifying the information, but with the person doing the verification. Humans live in pursuit of desires or ideals. Desire and ideals prevent humans from seeing facts as they are. In the end, people are deceived because the information given is not properly verified.
Humans should not deceive others, but they should not be deceived either. In particular, you should not be deceived by yourself. In other words, you should not be deceived by your desires and ideals.