The bad report delivered by the spies prompted the people to complain, “B’sinas Hashem osanu hotzi’anu mei’Eretz Mitzrayim,” (1:27) that it was because of his hatred for them that G-d took them out of Egypt. Of course, quite the opposite was true. Everything Hashem had done for Bnei Yisrael was for their benefit and motivated only by his love for them. The baseless crying caused by this complaint, which occurred on the night of 9 Av, planted the seeds of churban.
The Sefas Emes (5642) writes that way to rectify this sin is to develop the opposite perspective, to see even in that which appears painful and tragic the love of Hashem for Klal Yisrael.