(א) כִּ֤י יְבִֽיאֲךָ֙ יְהוָ֣ה אֱלֹהֶ֔יךָ אֶל־הָאָ֕רֶץ אֲשֶׁר־אַתָּ֥ה בָא־שָׁ֖מָּה לְרִשְׁתָּ֑הּ וְנָשַׁ֣ל גּֽוֹיִם־רַבִּ֣ים ׀ מִפָּנֶ֡יךָ הַֽחִתִּי֩ וְהַגִּרְגָּשִׁ֨י וְהָאֱמֹרִ֜י וְהַכְּנַעֲנִ֣י וְהַפְּרִזִּ֗י וְהַֽחִוִּי֙ וְהַיְבוּסִ֔י שִׁבְעָ֣ה גוֹיִ֔ם רַבִּ֥ים וַעֲצוּמִ֖ים מִמֶּֽךָּ׃ (ב) וּנְתָנָ֞ם יְהוָ֧ה אֱלֹהֶ֛יךָ לְפָנֶ֖יךָ וְהִכִּיתָ֑ם הַחֲרֵ֤ם תַּחֲרִים֙ אֹתָ֔ם לֹא־תִכְרֹ֥ת לָהֶ֛ם בְּרִ֖ית וְלֹ֥א תְחָנֵּֽם׃ (ג) וְלֹ֥א תִתְחַתֵּ֖ן בָּ֑ם בִּתְּךָ֙ לֹא־תִתֵּ֣ן לִבְנ֔וֹ וּבִתּ֖וֹ לֹא־תִקַּ֥ח לִבְנֶֽךָ׃ (ד) כִּֽי־יָסִ֤יר אֶת־בִּנְךָ֙ מֵֽאַחֲרַ֔י וְעָבְד֖וּ אֱלֹהִ֣ים אֲחֵרִ֑ים וְחָרָ֤ה אַף־יְהוָה֙ בָּכֶ֔ם וְהִשְׁמִידְךָ֖ מַהֵֽר׃
When the Lord your God brings you to the land that you are about to enter and possess, and He dislodges many nations before you -- the Hittites, Girgashites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites, seven nations much larger than you -- and the Lord your God delivers them to you and you defeat them, you must doom them to destruction: grant them no terms and give them no quarter. You shall not intermarry with them: do not give your daughter to their sons or take their daughters for your sons. For they will turn your children away from Me to worship other gods, and the Lord’s anger will blaze forth against you and He will promptly wipe you out.
אמר רבא אטו התם משום קדושה ולאו קדושה הוא דלמא מוליד בן ואזיל פלח לעבודת כוכבים וה"מ בהיותן עובדי כוכבים כי מגיירי בישראל שרו
Rava, is the reason for the prohibition “do not intermarry with them” a matter of sanctity? Rather, it is out of fear that the intermarried couple will have a child whowill worship idolatry. This prohibition against intermarriage applies only againstnon-Jews, but if they convert, they are allowed for marriage.
https://www.pewforum.org/2013/10/01/chapter-2-intermarriage-and-other-demographics/
The new Pew Research survey finds that, overall, 56% of married Jews have a Jewish spouse, while 44% of Jewish respondents are married to a non-Jew. Among Jews by religion who are married, 64% have a Jewish spouse and 36% have a non-Jewish spouse. By comparison, Jews of no religion are much more likely to be in mixed marriages; just 21% of married Jews of no religion are married to a Jewish spouse, while 79% are married to a non-Jewish spouse.
Rates of intermarriage vary considerably among the major U.S. Jewish movements or denominations. Virtually all Orthodox respondents who are married have a Jewish spouse (98%), and most married Conservative Jews also have Jewish spouses (73%). Half of Reform Jews who are married have a Jewish spouse. Among married Jews who have no denominational affiliation, 31% have a Jewish spouse.
The survey also suggests that intermarriage is much more common among Jewish respondents who are themselves the children of intermarriage. Among married Jews who report that only one of their parents was Jewish, fully 83% are married to a non-Jewish spouse. By contrast, among married Jews who say both of their parents were Jewish, 63% have a Jewish spouse and 37% have a non-Jewish spouse.
https://jewishweek.timesofisrael.com/interfaith-families-increasingly-jewish/
A 2015 survey done in greater Boston found that 57 percent of children of intermarried parents were raising their children exclusively Jewish; a 2017 Washington, D.C., survey found that 61 percent of children of intermarried parents were being raised exclusively Jewish and another 14 percent were being raised Jewish and another religion. Only 1 percent were being raised in a different religion entirely. Since 2003, the percentage of children being raised exclusively Jewish by intermarried parents has increased from 45 percent to 61 percent in the nation’s capital.