The letter below by the Lubavitcher Rebbe is in the book The Letter and the Spirit, volume II page 57:
"By the Grace of God
27th of Sivan
"Greeting and Blessing:
"...an Orthodox Rabbi cannot in all conscience recognize the Conservative and Reform points of view, inasmuch as both of the latter do not accept the Written and Oral Law. Hence these movements and their representatives cannot be recognized as legitimately representing the Jewish religion, inasmuch as they reject it. This has been unequivocally ruled by the Rambam and other authorities that followed him, who have established the laws and attitudes of the Shulchan Aruch, leaving no room for doubt or discussion on this basic issue.
"From the above it follows immediately that the activities of such dissident groups cannot be recognized as Jewish religious activities within the definition of Jewish religion. Therefore, Orthodox Rabbis cannot, in all conscience, be members of a body or organization together with representatives of the non-Orthodox points of view, namely, of the Conservative and Reform movements, inasmuch as participation and affiliation in such a body or organization would ipso facto constitute a recognition of the Conservative and Reform interpretation of Judaismas being legitimate parts of the framework of the Jewish Religion, in direct conflict with the unequivocal Psak Din of the Rambam and other autyhorities, as mentioned above..."
On June 26, 2017 Amanda Borchel Dan wrotel "Starting in the year 2000, following a long legal and public awareness battle, liberal Jews have had the right, granted by the State of Israel, to pray in the southern section of the Western Wall plaza...The egalitarian area is often nicknamed “Robinson’s Arch” for the famous archaeological artifact found there...The 450-meter larger platform was opened with much fanfare in August 2013 by Naftali Bennett, then the religious affairs minister. At the time, Bennett said it was meant to be “an interim but primary place of worship for Jewish egalitarian and pluralistic prayer services.”
"Bennett was spurred by court cases brought by the Women of the Wall group, led by [the Reform Movement's] Anat Hoffman, whose members desire to worship at the Western Wall with prayer shawls and phylacteries and read from the Torah... The 2013 temporary platform was met by skepticism — and in some cases disdain — by leaders of Diaspora Jewry and the Women of the Wall, who at that point sought a space at the more normative Western Wall complex..".
Below are some major differences between Orthodox Judaism and the Reform Movement:
1. Orthodox Judaism considers a Jew a person whose mother is Jewish or who converted. The Reform Movement considers a Jew a person with a mother or father Jewish. Many Reform Jews do not have a Jewish mother.
2. Reform clergy officiate at mixed marriages between Jews and gentiles, sometimes along with Christian clergy. Orthodox Rabbis officiate at marriages only among Jews.
3. It is an obligation for Orthodox Jewish men wear tefilin everyday except shabat and yom-tov, The Reform Movement does not require the use of tefilin. Most Reform Jews, including clergy, do not use tefilin.
3. All Orthodox Synagogues have the bima located so people would face Jerusalem's Temple Mount when they pray, many Reform Temples do not.
4. Orthodox Judaism wants the construction of the third Temple, Reform does not. That is the reason why the Reform Movement calls synagogues "Temples" something Orthodox Judaism does not because for Orthodox Judaism the Temple can only be in Jerusalem. Reform prayer books deleted verses calling to rebuild the Temple in Jerusalem.
5. The Talmud (Oral Torah) is holy for Orthodox Judaism. For the Reform Movement, the Talmud is not binding, Rabbi Daniel Freelander, senior vice president of the Union for Reform Judaism explains "Text study is very important to us, but we focus on the Ur-text, on Torah in particular. That’s an interesting contrast between Reform and Orthodox. Talmud, Oral Law, is not our core text..."
"We’re aggressively pushing Torah and Tanakh study; we’re not aggressive at a North American level of pushing Talmud study. Talmud study remains important, but it’s not as central, certainly doesn’t rise anywhere to the level of a daily study encouragement for us...We see ourselves as successors reclaiming the core Torah text.
"The rabbis of today and of yesteryear are of equal authority. The amoraim [rabbinic sages quoted in the Talmud] do not get special consideration. Contemporary commentary is equally as interesting and holy, if you will...We’re creating new sacred texts. Only time determines what the Jews will value for the long term… We’re not assigning Divine weight [to Talmudic rulings]. They don’t carry more weight than contemporary Jewish philosophy… Oral Law we do not find to be binding."