Where are the Jews who died before Jesus came to Earth? Will they be saved when Christ returns at His Second Coming?
At any time in history, only those who express faith in the promised Messiah (whether a Jew or Gentile) are saved, and those who do not possess such faith are eternally lost, as the Bible teaches:
Rom. 2:9 There will be tribulation and distress for every soul of man who does evil, of the Jew first and also of the Greek,
Rom. 2:10 but glory and honor and peace to everyone who does good, to the Jew first and also to the Greek.
Rom. 2:11 For there is no partiality with God.
Rom. 2:12 For all who have sinned without the Law will also perish without the Law, and all who have sinned under the Law will be judged by the Law;
Heb. 9:27 And inasmuch as it is appointed for men to die once and after this comes judgment,
For more information on the salvation of Jews, please read about the remnant of Jews.