If someone has relations with a married woman even if he gives Tzedakah in secret he will not be saved from the Din of Gehinom.
Anytime the Torah says Hishamer, Pen, or Al it is a Lo Sa'aseh.
Someone who is haughty will eventually be diminished. (1)
Hashem Yisbarach is with those that are humble. (2)
Someone who is haughty is fit to be uprooted like an Asheirah tree and the dirt of his grave will not move upon Techiyas ha'Mesim.
Hashem Yisbarach says that he cannot live in the same world with one that is haughty.
Rav says that a Talmid Chacham must have an eighth of an eighth of haughtiness. (3)
A person's Tefilah is only answered if he softens his heart.
Someone who is humble is regarded as if he brought all of the Korbanos.
If a person is humble his Tefilah is not turned away.
A person who calculates his ways in this world will merit seeing the deliverance of Hashem Yisbarach. (4)
If a wife is warned not to talk with a certain man it is not a valid Kinuy. (5)
A Safek Sotah whose husband dies without children requires Chalitzah, but she may not do Yibum.
A BIT MORE
1. If he does Teshuvah he will live out the rest of his days like Avraham, Yitzchak and Yakov.
2. This is learned from the fact that Hashem Yisbarach gave the Torah on the humble mountain of Har Sinai rather than on other mightier mountains.
3. Rebbi Nachman Bar Yitzchak says that one should not have even a little bit of haughtiness.
4. A person should calculate the cost of doing a Mitzvah versus the reward for the Mitzvah in Olam ha'Ba.
5. If the wife is warned not to seclude herself with a certain person and she talked to that person it is not regarded as a Setirah.
TZEDAKAH AS AN ATONEMENT
If someone has relations with a married woman even if he gives Tzedakah in secret he will not be saved from the Din of Gehinom. The Midrash says that if someone has relations with a married woman and subsequently a poor person comes to his door and he gives him Tzedakah and he says that Hashem Yisbarach did not arrange that a poor person should come to his door unless He has forgiven him for his sin, about such a person the Pasuk says Yad l'Yad Lo Yinakeh. (Tosfos Shantz)
A HUMBLE SPIRIT
There are certain characteristics that a person may not use the middle path for this characteristic and rather he must distance himself from them to the furthest extent. One of those characteristics is haughtiness. It is not sufficient for a person to be merely humble, he must have a humble spirit and his spirit should be exceedingly low. Therefore the Torah states regarding Moshe Rabeinu that he was very modest and it does not just state that he was modest. (Rambam Hilchos De'os 2:3)