Strife is so severe, that it leads to the endangerment of lives. For, as a result of the quarreling that existed between the shepherds of Avraham and the shepherds of Lot, each of them separated from one another. This resulted in Lot going to Sodom, and almost being destroyed [along] with [the people of Sodom].
[The sin of] strife is so severe, for it brings a person to receive lashes, as it says, “When there shall be a quarrel between people…” (Devarim: 25; 1), “And if the evildoer is found liable [to receive] lashes…” (Devarim: 25; 2) What caused him to [receive] lashes? [Based on the aforementioned verses], you would say, [that] the [sin of] strife [led to the lashes].
Strife is such a severe [sin, to the extent that] that it leads to death, as it says, “And when men shall quarrel and they smite a pregnant woman…” (Shmos: 21; 22), “And it shall be that if [that action] resulted in death, and you shall give one life…” (Shmos: 21; 23) What caused this [death]? [Based on the above], you would say, the quarrel.
[Furthermore], our Sages of Blessed Memory have said (Derech Eretz Zuta, chapter 9): “Strife in the house leads it to eventually be destroyed. [The Sages said that if there is] strife in the synagogue, [the attendees] will eventually scatter [away from that synagogue]. Not only that, but eventually [that synagogue] will lie desolate. If there is strife in a city, there is murder in the city. Two Torah scholars who live in one city, and [the same goes for] two courthouses [in one city], between whom there exists strife, in the end they will die. Not only that, but [Abba Shaul said that] a quarrel between courthouses brings destruction to the world.” You should known that this is the case, [that destruction results from the sin of strife which exists between two courthouses], for the entire time that there is peace in the court below, [in this world], there is peace in the Heavenly Court, as it says, “The One Who builds the stratum of Heaven…” (Amos: 9; 6) When is this the case [that HaShem builds the stratum of Heaven]? [HaShem builds the stratum of Heaven] at the time that “…His group is firmly established on earth…” (Amos: 9; 6) [The aforementioned] means [that]: At the time when the Jewish People are bound together as one group, and there is peace between one another, [HaShem builds the stratum of Heaven].
 According to the text of “Derech Eretz Zuta”, quoted in sefer “Shmiras HaLashon”, we learn that a synagogue in which there is strife will eventually be disbanded – “להתפזר”. However, the text of “Derech Eretz Zuta”, included in a Vilna set of Shas, reads that the synagogue will be cut off – “להתגזר”. The Vilna Gaon has a varying text which states that the synagogue in which there is strife, will, in the end, become a house of idol worship.
 “Courthouses” refers to courts of Jewish law.
 In maseches “Sotah” (49a), we learn that if there are two Torah scholars in a city who are not pleasant to each other in halacha, one dies and the other is sent into exile.