The truth is one. We accept 4 madhhabs as true. How is it possible?

A liquid (water) is given 5 different judgments based on 5 different patients. For instance, it is medicine for the disease of a person. Then, it becomes obligatory (wajib) for him medically. It is harmful like a poison for another. It is forbidden (haram) for him medically. It is a little harmful for another. It is makrooh (abominable) for him medically. It is useful for another. It is sunnah for him medically. It is neither harmful nor useful for another. It is mubah (permissible). 5 of them are true depending on the patients. One cannot say it is only wajib.

As it is seen in the example, the judgments can change based on the situations of the people who follow those madhhabs. They are different for different situations.