Many "white supremacists" and Jew haters attempt to use these scriptures to show that Jews are "bad." Below are scriptures and pertinent footnotes which serve to answer your question, borrowed from the Aramaic English New Testament:
Revelation 2: 9. I know your works and the affliction and the poverty (yet you are rich) and the railing which is from them who say they are Jews and they are not, but are of the congregation of haSatan.
Revelation 3: 9. Behold, I will give them of the Knesset of Satan, who say they are Jews, and are not, but lie; behold, I will make them to come and do submissions before your feet; and to know that I have loved you. 10. Because you have kept the Word of my patience, I also will keep you from the hour of temptation that is to come on all the inhabited world to try them who dwell on the earth.
1 Thessalonians 2: 14. For you, my Brothers, became assimilated to the assemblies of Elohim in Judaea, the persons who are in Y’shua the Mashiyach in that you so suffered, even you from your own countrymen as also they from the Jews, 15. the persons who slew our Master Y’shua the Mashiyach and persecuted their own prophets and us; and they please not Elohim and are made hostile to all men; 16. and they forbid us to speak to the Gentiles that they may have life; to fill up their sins at all times. And wrath comes on them to the uttermost.
 Aramaic "Knooshta" or the Hebrew "Knesset" simply means to assemble; Beit Knesset (house of assembly) is the place for a community to come together for prayer. There is no deep mystery or architectural wonderment or portraits which attempt to relay the grandeur of the Almighty within the physical building of the Beit Knesset, nor is there some mystical spiritual power that denotes the structure itself as Set Apart unto the Almighty. In the days of Y’shua there were an estimated 450 Beit Knessets in Jerusalem, most being humble and very simple yet functional places of meeting to pray, hear Torah and facilitate local collective spiritual needs. The Temple in Jerusalem always was and will always be the only "House of Elohim" contrary to much of Christendom which views the "house" itself as something "holy."
The Greek word for "Beit Knesset" is "synagogue" which denotes a Jewish place of worship. As Greece is the home of the longest continuous Jewish presence in the European Diaspora, going back 2300 years, there were certainly warm relations between Greeks and Jews – until, of course, the rise of anti-Semitic Christianity. But here in this verse we see yet more evidence of the pagan influence in Greek translation, "the synagogue of Satan." The "synagogue" in the Greek mind is a place where Jews meet, whereas a "Knooshta" could refer to any kind of meeting place, for any purpose, for anyone. The writer, Mar Yochanan (John) himself attended a "synagogue." To put "synagogue" in this passage implies that all Jews are meeting with the "devil" but that is clearly not in the original message. What Mar Yochanan is talking about is an "evil assembly" or a conspiratorial group who desire their destruction and who happen to be of Jewish bloodline. Certainly the Jewish "establishment" were clearly fearful of Jews who preached Mashiyach Y’shua and Torah. So in the context of this verse, the official religious body of Israel has exercised power wrongly against the Netzarim Jews. That is what Mar Yochanan is talking about; certainly not a wholesale indictment against his own people!
 Many Rabbis warn Jews to not teach Torah to the Gentiles; they forbid it because according to their perverted religious perspectives, they’ve concluded that Gentiles would "only mess it up" – proving again that Jewish humor is indeed alive and well! Most Christians have never had opportunity to learn Torah, just like most Jews have strictly been warned away from Y’shua Mashiyach. Had Rabbinical Judaism taken an active role to make Torah available (understandable) to everyone, there would be much less anti-Semitism in the world. Rather than viewing Jews as "the Christ-killers" a healthy portion of the two billion Christians on earth would better understand that Jews and Gentiles are part of Mashiyach’s Universal family and congregation.
Note from The Refiner's Fire: Many tend to forget that if "the Jews" hadn't been scattered into the nations (Ezekiel 36:19), the world would never have heard of YHWH or His Son Yeshua, and the God of Abraham, Isaac and Jacob would have been the secret of tiny, little Israel! While the Jewish rabbis were certainly responsible for initiating Yeshua's death (1) there was a "mixed crowd" who spat and threw stones and harassed Him; (2) the Gentile Romans were the ones who flogged, pulled out His beared and beat Him half to death; and (3) the Gentile Romans actually nailed Him to the cross/stake.
What most tend to forget also is that Yeshua HAD to die in order to become our Final SIN Sacrifice! To lay blame on "the Jews" for "killing Jesus" and to make them out as the "bad guys" is completely ignorant and vicious on several levels. People who make such comments need to re-read their Bibles so they can get a clue as to what it's all about.
 "Congregation of Elohim" from eidta d’Alaha is preferred over "church of God" as this is the true meaning of the Aramaic phrase, nearly identical to the Hebrew phrase adat YHWH that is used in the Tanakh to describe Israel (Numbers 27:17, 31:16; Joshua 22:16). Paul makes the point that the conduct of these men against Torah is at fault, not their ethnicity. Certainly, it was an abomination for Jewish ancestry to persecute the prophets of YHWH and bow down to paganism and idols. It is arrogant for religious Jews to reject Gentiles and not include them as equals in the Malchut Elohim. All this and more is what constituted the collection of Jews who became known as "the assembly of satan." After all, Torah commands that there is ONE Torah for Jew and ger (sojourner), so then on what authority do the Pharisees and their cohorts deny YHWH and say no to Mashiyach? Y’shua said these men hold the keys to salvation but will not enter into the Kingdom themselves, nor will they permit others to enter.
However, to extrapolate that Paul lays blame on all Jews for these crimes shows profound ignorance of basic human reality and Jewish cultural fact. On another note, it wasn’t until Marcion "the heretic" that an all-Gentile "Christian church" prohibited Jewish attendees. The word "Church" has its origin with "Circe or Circ" pronounced "Kirch." Circe was the daughter of Helios, a Greek goddess and sun deity. The halo (circle) of light that Christians painted over the heads of "the saints" formerly belonged to Circe.
There are some teachers trying to show that "synagogue of Satan" refers to either non-Jews being allowed to be Temple priests, or those having come from questionable lineages such as Ham's lineage, etc. Regardless, what both Yeshua and Paul were referencing concerning those "who say they are Jews, and are not" were those people who proclaimed to be Jewish (meaning they were born from Jewish lineage and were Torah observant) while being disobedient to the Torah, in general - saying one thing and doing another.
For instance, Paul's discussion concerning circumcision (Galatians 5:1-7) referenced the idea that it does no good to go through the motions of being circumcised if you're not going to be obedient to YHWH in other ways. Obedience to the circumcision command merits NOTHING if you don't bother being a true Torah observant servant to YHWH; all it does is to make you a hypocrite. You do not belong to God if you "talk the talk but don't walk the walk"....
Bottom line: Who cares what the lineages of the Temple priests were? After all, we are all ONE in Messiah (including those Jews who don't yet know Him), so what difference does lineage make? The fact is, certain priests in Yeshua's time were hypocrites in one way or another, wanting to hang onto their religiosity and man-made ideas rather than to concentrate on Truth and being willing to keep learning and growing and producing actual fruit for YHWH.