How can the hadiths of intercession—which mention people coming out of Hell who had an atom's weight of faith in their hearts—be reconciled with the statement that some groups will abide eternally in Hell?

The hadiths about intercession are authentic and affirm intercession for those who died upon monotheism, provided that Allah is pleased with the intercessor and the interceded for, and grants His permission. As for disbelievers, they will abide eternally in Hellfire, though the torment may be lightened for some of them, such as Abu Talib, through the intercession of the Prophet, peace and blessings be upon him. The entry of all monotheists into Paradise is indicated by the Prophet’s hadith: “Every prophet has a supplication that is answered… And I have reserved my supplication as intercession for my Ummah on the Day of Resurrection, and it will reach, Allah willing, whoever dies from my Ummah without associating anything with Allah,” and the hadith: “My intercession is for the people of major sins from my Ummah.” So, whoever has an atom’s weight of faith in his heart will be brought out of the Fire if he enters it.