כֹה אָמַר אָחִ יָך יִשְרָאֵל (Numbers 20:14). Look how Moshe speaks to Melech Edom. He calls himself a brother, he recounts Klal Yisroel’s Tzaros, and how Hashem saved them. Doesn’t Moshe realize that he’s speaking to the descendants of Eisav HaRasha, about whom it says: ְּועֶבְָּּרתוֹ שְּמָָּּרה נֶצַח (Amos 1:11) His hatred lasts forever! “Eisav So'nei L’Yaakov is a Halacha”. If anything, Melech Edom would be overjoyed hearing the Tzaros of Klal Yisroel!
We find the same thing by Dovid, who was warm and trusting to the evil Naval HaCarmeli, and he calls himself: “Your son”! And Dovid trusts Shaul, even after Shaul threw a spear at him! In contrast, look at Doson and Aviram who were always suspicious of Moshe Rabeinu their savior. They go against him, even at the expense of putting their lives in danger.
Just as they didn’t trust people, so too they didn’t trust Hashem. They left over from the Mon; out of fear they wouldn’t have any tomorrow. A negative person is in his own warped world. When they were angry at Moshe, they complained how they missed Mitzrayim, an Eretz Zavas Chalav u’Dvash. How ludicrous!
By the negater, anything that’s not his is considered Zavas Chalav u’Dvash. And whatever he has, is worthless. He lives in a total Dimyon of mistrust and suspicion. Negative thinking is loaded with all kinds of Dimyonos and problems that aren’t real and will never happen.