He has also served as chairman of the Constitution, Law and Justice Committee of the Knesset during the term of the 36th Government of Israel.

Kariv served in the Israel Defense Forces Intelligence Corps under the Haman Talpiot program.

Following five years of service, during which he completed the officers program with honors, Kariv went to study at the Hebrew University of Jerusalem.

During his academic studies, Kariv established Progressive Movement student networks on campuses around the country.

Kariv initiated the establishment of Keren Be'chavod ('Be'chavod Fund) – the Reform Movement's humanitarian aid foundation, and "Kehilat Tzedek" – the training and guidance center for people of all Jewish sects in the field of social action.

He has published several position papers on a variety of topics, including a proposal for the re-organization of religious service provisions in Israel, a suggestion for separation of religious institutions from state bodies, Israeli public space on the Sabbath and a report on the crisis of conversion.

Kariv is regularly invited to represent the Reform movement before Knesset committees and in a variety of other public settings.