Achdus
The Shlah HaKadosh taught, "One machlokes banishes a hundred parnassos." The Chasam Sofer brought a hint to this from this week's parashah. It states (44:28) ויצא טרף טרף ואומר מאתי האחד, "The one went away from me, and I said, 'He has surely been torn to pieces.'" The word טרף means torn, but it can also be translated as parnassah (see Tehillim 111:5, נתן טרף). Therefore, we can translate the pasuk, מאתי האחד ויצא, when achdus leaves me, טרף טרף ואומר, I will say that the parnassah is torn. The parnassah is lost when there isn't achdus.
The Chasam Sofer said that this is also alluded to in the pasuk (Tehillim 147:14) גבולך השם ישביעך חיטים חלב שלום, "Within your borders He makes peace; with the best of the wheat He will satiate you." The Chasam Sofer explained, שלום גבולך השם, when peace is very important to you, ישביעך חיטים חלב, you will have parnassah in abundance.
The Gemara (Moad Katan 28.) says, "Parnassah isn't dependent on one's merit. It is dependent on one's mazal." If a person was born with a mazal that isn't conducive for parnassah, is there no hope of having parnassah? Is there a way he can become wealthy? Tosfos (Shabbos 156.) says that when one has a great merit – a very great mitzvah – his mazal can change. Increasing peace is a great merit. Therefore, when one increases peace among Yidden, his mazal can change, and he can have parnassah and wealth. Therefore, השם ישביעך חיטים חלב שלום גבולך, when there is peace, there is parnassah and wealth.
The family of Reb Moshe Betzalel zt'l hy'd (brother of the Imrei Emes zt'l) once complained that they didn't have parnassah. Reb Moshe Betzalel told them, "The first thing we must be careful of is that there shouldn't be any anger or machlokes in our home because one machlokes banishes a hundred Parnassos."
Beis Yaakov (a student of Rebbe Bunim of Peshischa zt'l) writes, "I heard from my rebbe that if a person is having trouble with בנים גידול צער, raising his children, it is a segulah to be cautious from machlokes and to seek peace, and to be from the people who accept the humiliation of others and they don't answer back. This will be his cure."
Rav A. Y. Steinberg Shlita from Lakewood tells the following incident that happened to him a few years ago. His daughter got an infection on her leg. Matters became serious, and she lost consciousness. The doctors said that she wouldn’t live until the morning. Baruch Hashem, she survived, but she was unconscious for several weeks. One day, Reb A. Y. Steinberg was very tempted to say lashon hara (what people call "a juicy lashon hara"), but he held back. Then, he immediately said a tefillah: "Ribono Shel Olam, I closed my mouth from saying lashon hara. In this merit, allow my daughter to open her mouth."
Ten minutes later, his wife called him from the hospital. She said that their daughter was crying. This was a good sign; it was the beginning of her recovery.
I heard the following remarkable story from the baal hamaaseh. There was a couple who didn't have children for ten years. They davened and tried many segulos, but the doors of heaven remained sealed. The husband went to one of the gedolei hador, who advised that they should seek whether they need to rectify something in the matters of ben adam l'chaveiro.
The wife remembered that when she was a girl, it was very lebedig (in a negative way) in her class. She and her classmates caused their teacher a lot of aggravation and tzaros. She called up her classmates from years ago and discovered that half of the class was suffering from great yesurim. Some weren't married yet, some didn't have children, etc. All these women came to the home of the teacher whom they caused so much trouble and told her about their tzaros and that they thought that perhaps it was all because of their bad behavior in the classroom years back... The teacher cried when they spoke to her, and she said, "You have no idea how much I suffered that year!" She told them some of the pain that she had then, and she told them that, in some ways, she still suffers from what they did to her. She said, "I forgave you immediately when you caused me the tzaros, but the pain hasn't left me until today. It feels like it happened just a few days ago, although it happened several years ago."
The girls asked daas Torah from one of the gedolim of our generation. He ruled that they should give her money, as much as she requested, to appease her for what they did. The teacher forgave them on the condition that the story becomes known so people will know how severe it is to cause harm to others.
Remember: Causing pain to others has consequences, and peace and unity bring many brachos. Choose the latter.