"On the day healthy flesh appears in it, it shall be impure" (Vayikra 13:14). There is a day on which you look, and there is a day on which you do not look. From here we derive that a chassan is granted all seven days of his celebration. Similarly on a festival we do not pronounce anyone impure (Rashi). We do not mar the celebration of a chassan or of anyone during yom tov (Sifsei Chachamim).
The kohein shall look at the affliction (nega), the kohein shall look at it (v'ra'ahu) and make him impure (13:3). Alternatively, v'ra'ahu means he shall look at him. Objectively, the person has a nega. But the kohein looks at the whole person. If he is a chassan or it is a yom tov, the person is not examined and remains pure (Mesech Chochma).
Perhaps this halacha contains a critical lesson for a chassan, and kallah as well. The first week of marriage can be very disturbing. Suddenly, the chassan or kallah may discover a nega that could not have been seen earlier. Personal habits or physical blemishes unnoticed during courtship and engagement become apparent upon marriage.
A new spouse may, as recent works have described, have a different way of squeezing toothpaste from a tube, which can be disconcerting. More serious and objective flaws of personal conduct or appearance can lead to disappointment or worse.
What is the proper response? Look at the whole person. You chose to marry an individual who has many wonderful attributes. You were attracted by your spouse's positive traits and unique character. Do not look at the negative, at the new blemish or flaw that marriage exposes.
The chassan must look at the kallah as a wonderful whole person, and overlook any newly discovered negatives. In turn, middah k'neged middah, we overlook his negatives and consider him, the whole person, pure.
The laws of impurity of a nega return after the week of celebration. But the lesson of overlooking one's spouse's shortcomings must last for a lifetime.
On holidays, all of Israel gathered in Yerushalayim. Persons deemed ritually impure all year long were granted the status of chaveirim, expert practitioners of ritual law (Chagiga 26a). Again, since we are all required to overlook the flaws of others usually designated as "am ha'aretz", the kohein does not examine our negaim on yom tov, and we remain pure.
After the holiday the impurity of the am ha'aretz returns. But the lesson of overlooking the shortcomings of others must remain all year long.
One who judges his friend favorably, Hashem judges him favorably (Shabbos 127b). This cannot mean giving others the benefit of the doubt, since Hashem has no doubts. Rather, we should not judge the clear faults of others objectively, but find an extenuating circumstance which avoids a negative judgment. Then Hashem, midda k'neged midda, will judge us favorably despite His clear knowledge of our faults, based on extenuating circumstances. (Rav Chaim Shmuelevitz).
Our obligation to focus on the positive and overlook blemishes applies to those closest to us, such as a spouse, especially a new one. It extends to those on a lower spiritual level, such as an am ha'aretz. And it includes friends with whom one interacts, and all Jews who, in this sense, are chaverim.
The response, both by the kohein, who overlooks our nega, and Hashem, who overlooks our sins, is commensurate with our efforts. Viewing others positively is a critical component of spiritual purity.