"Only those who hear will respond [to the call]," meaning: the believers. "But the dead, Allah will resurrect them." Al-Hasan said: By "the dead," he means the polytheists.
And regarding His saying: "Allah will resurrect them," it means: those whom Allah favors with faith, so He revives them from their polytheism, "then to Him they will be returned" on the Day of Resurrection.
Surah al-An'am from verse (37) to verse (39).