Why does it specify "Bakeshu Es Hashem Kol Anvei ha'Aretz"?
Radak: Even though most of Yisrael sinned, many good people who fear Hashem remained, like Hashem told Eliyahu "v'Hish'arti b'Yisrael Shiv'as Alafim Kol ha'Birkayim Asher Lo Kar'u la'Ba'al v'Chol ha'Peh Asher Lo Nashak Lo" (Melachim I, 19:18). It says about Churban ha'Aretz "Nasenu Es Nivlas Avadecha Ma'achal l'Ohf ha'Shamayim Besar Chasidecha l'Chayso Aretz" (Tehilim 79:3). Even though there were people who served Hashem and His Chasidim, they fell to the sword with the Resha'im - "Ki Ad Tzedek Yashuv Mishpat" (ibid. 94:15).
Malbim: After addressing "ha'Goy Lo Nichsaf" (1), and the straw (commoners), it teaches that even though the commoners do not want to repent, you, Anvei ha'Aretz (Tzadikim)...
How does one seek Tzedek and Anavah?
Radak: Strive to return others to the good path.
Malbim: Be humble in front of Hashem in fasting and prayer.
What is the meaning of "Ulai Tisaseru"?
Radak: You will be hidden and not die via the sword with the Klal, but he did not promise them [to be spared from] Galus. The decree was made already in the days of Menasheh and was told to Yoshiyah ha'Melech "v'Ne'esafta El Kivrosecha b'Shalom v'Lo Sir'enah b'Chol ha'Ra'ah Asher Ani Mevi Al ha'Makom ha'Zeh" (Melachim II, 22:20).
Malbim: Even though Hashem's anger will be against ha'Goy Lo Nichsaf, you will be hidden on the day of His anger, and the Tzadikim will be saved.
What is the significance of "Af Hashem"?
Radak: Even though it will be a day of Hashem's anger against you, your evil neighbors should not rejoice over you.