Where does it say in the bible that first the Jews will saved then Gentiles? Revelations?

We are having a good-natured battle in Sunday school about the fact that Jews will be rescued before gentiles, as i recall from revelations, but the 7th graders thinks that Jews will not because they do not believe in Jesus. I'm not trying to start a debate on Yahoo about Religion and whom will get into heaven, i do not need hate mail, i simple would like to know what the scripture is that says the Jews will saved before the gentiles.