I have copied and pasted some of this from another thread:
Why it is important that we accept and identify the 'Jewish' bloodline.
It is not easy for anybody to become a Jew and if they do, they usually marry into Jewry and their descendants become part of the bloodline. So although Jews may be a mixture of races they still descend from common ancestors.
God's plans for the End Times are based upon promises made to the bloodline. These are quite specific. The Jews of 2,000 plus years ago are all dead now so the 'remnant' chosen will come from their descendants so it is important that God preserves the descendants of David and so on. Even if they don't know who they are - God does.
With Christians there is no bloodline promise, only a promise to those who believe, so anybody can be a Christian - Black, White or Yellow - French, Finnish or Filipino.
That is why Jews have been persecuted because Satan knows that if they are wiped out, God will have failed to keep his word and by proving God to be a liar, Satan will have won the battle.
You don't need to destroy every last Jew on Earth, but by exterminating 90 or 95% of them there is a good possibility that the important tribal bloodlines will disappear. Satan has always used evil men to carry out his work and in the 1920s and 1930s he probably knew that the nation of Israel was about to be formed, so in a last desperate effort to complete his final solution, he carried out his most successful pogrom of all time, when 6 million Jews were murdered by the Nazis. Hitler also collaborated with Amin al-Husseini and if he had successfully won World War 2, his next focus would have been on exterminating all the Jews in the Middle East.
Now that Israel exists and is a safe haven for Jews, Satan has focused most of his anger against discrediting Israel in an attempt to remove international support from her. He wants to see Israel destroyed and his evil Islamic followers are more than happy to do the job.
The whole idea behind Jesus being Black is nothing to do with racial equality or making him more accessible to ethnic minorities, it stems from a recent ideology to discredit the Israelis.
A lot of people have lost the argument about the Jews having a right to their own homeland so now they have created a new heresy to discredit the Jews of modern Israel by saying that they are not descended from the original Jews, but are imposters.
By claiming that Jesus was Black (and thus the original Jews were Black) the Ashkenazi Jews and other groups such as Sephardi Jews are made out to be false Jews who are not descended from the twelve tribes of Israel.
Remember that Jesus came in the flesh as a Jew. This is very important. So it is important to establish biologically, who a Jew really is.