Born into a rabbinical family in Vilna, Samuel Mohilever was also a rabbi. Ordained in 1842 at the Volozhin yeshiva, he was offered rabbinical posts in several communities in the Vilna area. In each place, he became active in community affairs. An early member of the Hovevei Zion in Russia, he became one of the founders of religious Zionism.
In the 1870s, Mohilever was one of the rabbis who met with leaders of the maskilim in order to try to bring the two sides together. He was attracted to the concept and possibilities of settling mass numbers of Jews in Eretz Yisrael. This desire led to the founding of the Hibbat Zion.
In 1890, he led a group tour of Eretz Yisrael. In 1893, he initiated the concept of a mercaz ruhani (spiritual center) which became Mizrachi, the religious Zionist organization.
A member of the Zionist Organization, failing health prevented him from attending the First Zionist Congress in Basle in 1897. He died the following year.
His grandson, Josef Mohilever, followed in his grandfather's footsteps. Having received a traditional Jewish and Zionist education, he was also active in Zionist groups and was a government-appointed rabbi. He moved to Palestine in 1920 and settled in Jerusalem where he was deputy head of the Teachers Seminary and then head of the Hebrew High School.
Rabbi Samuel Mohilever had the proper background for taking stands on community affairs in eastern Europe in the early 1900s. On the philosophical side, he worked on cooperating with leaders of the more modern maskilim movement for the welfare of the Jewish people as a whole. As pogroms swept through eastern Europe and Russia, he approached both those who fled to Russia as well as the philanthropists to try to convince them to encourage Jews to go to Eretz Yisrael. These activities eventually led to the founding of the Hibbat Zion (love of Zion) movement, and later to the founding of the Mizrachi movement which joined the Zionist Organization in 1902. When other religious leaders withdrew their support of the Hibbat Zion because of their contact with the maskilim, Mohilever did not join them. He encouraged Pinsker and Lilienblum who wanted to organize the various local Hovevei Zion groups into one organization.
On the practical side, he was one of the leaders who influenced Edmond de Rothschild to help establish early settlements in Eretz Yisrael, particularly Ekron, which was intended for Jewish farmers from Russia. He also helped persuade Jews in Bialystok to settle Petach Tikva.
In 1883 he became rabbi of Bialystok, where his members granted him time to continue his public works. He was honorary president of the 1884 Hovevei Zion conference, as well as chairman of their conferences in 1887 and 1889. Under his influence, a board of rabbis was chosen to insure that settlement work in Eretz Yisrael would be carried out in accordance with Jewish tradition as much as possible. He was one of the rabbinical sources who allowed Jewish farmers to work their land during the shemitta year. One of the initial speakers of the founding conference of the Hovevei Zion in Odessa in 1890, he then led a group tour of Eretz Yisrael. Upon his return, he encouraged financial and physical support for settlement in Eretz Yisrael. A result of this effort was his initiative to form a spiritual to direct public relations and general information activities among Hovevei Zion members. This effort became Mizrachi, the religious Zionist organization. In recognition of his efforts, an orchard called Gan Shmuel was planted near Hadera for his 70th birthday.
Mohilever and his colleagues continued their work, especially among Orthodox Jews, and as a result, Mizrachi became the foundation of the religious Zionist movement. In 1902, four years after Mohilever's death, Mizrachi officially joined the Zionist Organization.
His last letter to the Jews of Russia before his death urged them to work to achieve a deep attachment to the commandment to settle in Eretz Yisrael, which he termed the foundation of the existence of our people.