1. Before the Torah which is our Constitution made us a nation, there were neither "Jews" nor "gentiles". Avrahan Itzhak and Yakov were "Bnei Noah" (ie:gentiles) in spite of the fact they undoubtedly have "Jewish genes" since they fathered the Jewish Nation! 2. Jews who have no belief in G-d are Jewish for being born into that Nation. 3. The DNA test is racist because if being Jewish was defined by DNA, no gentile could ever convert! The fact an "evangelical can be a better friend to Israel" does not make him Jewish, and a self-hating Jew is still a Jew. This general outline will clear your confusion. Stick to it and you will be safeguarded against all the theories that aim at undermining Jewish identity.
Suspect Bangkok bomber arrested, found with possible bomb-making materials (Reuters)
from the article: Report: DNA tests support Zimbabwe tribe's claim of Jewish roots