Rabbi Y. Oliver
Below is a compilation of translations of letters from the Rebbe concerning marital harmony.
One Should Only Rebuke One’s Wife With Soft Words
Don’t speak to your wife with harsh words. This will cause dispute and strife, and your goal will not be attained. Rather, speak with soft, calm words, as one speaks to his friend, and explain how one should not act in this manner, all in a soft manner, and then you will have an impact, and the goal will be fulfilled. This is crucial and very fundamental.
Sefer HaSichos 5703, p. 233.
Promoting Family Unity through Joint Shabbos Meals
One of the first steps toward promoting family unity is to strengthen the custom for the entire family to eat a joint meal on the night of Shabbos.
Letters from the Rebbe, Vol. 3, p. 135.
Benefit of Compromise in Marriage
I hope that over time you will you will reach the conclusion that [in marriage] sometimes one should compromise, and through a small compromise one can gain a great deal.
Igros Kodesh, Vol. 5, p. 81.
Don’t Emphasize Your Spouse’s Faults
Until Moshiach arrives, no one exists without faults. Thus, it is clear that just as one spouse has a fault, so does the other, and just as one would not want one’s own faults to be emphasized, so should one not emphasize and amplify the faults of the other. This is the way all Jews should relate to one another, but this applies all the more when relating to your husband, who is the father of your children.
My intent is not to criticize, but merely to draw your attention to the fact that your situation is not as forlorn as you present it, and it is not unusual, as it appears to you.
Each of you should ignore certain things, and is preferable that each of you find ways to bring peace in the home. Once this is attained, this is the vessel through which Hashem will provide blessings and success, good health, livelihood, and nachas from the children.
Igros Kodesh, Vol. 5, p. 61.