In summary: People fear the truth because they live in a lie.

Although, in my opinion, people believe false things because they are not fully prepared to accept the truth. The truth can actually hurt someone if this person is very identified or attached to falsehood. When a person is so ingrained to the illusion that it is falsehood, this becomes part of him, so leaving it is not easy, and truth will hurt, because the truth will be in opposition to something that person identifies with. Therefore, the truth can actually do us more harm than good, if we are not prepared for it. That is why it is important, I think, to let everyone walk their way to the truth without interfering, respecting the different beliefs that others have, and only engage in discussions with those who are willing to accept the truth and get away from their own beliefs.

So, falsehood is also necessary, because many people are not ready to accept the truth. Although not for that it is a good thing.