Judaism
Christianity was originally a sect of Second Temple Judaism, but the two religions diverged in the first century. The differences between Christianity and Judaism originally centered on whether Jesus was the Jewish Messiah but eventually became irreconcilable. Major differences between the two faiths include the nature of the Messiah, of atonement and sin, the status of God's commandments to Israel, and perhaps most significantly of the nature of God himself. Due to these differences, Judaism traditionally regards Christianity as Shituf or worship of the God of Israel which is not monotheistic. Christianity has traditionally regarded Judaism as obsolete with the invention of Christianity and Jews as a people replaced by the Church, though a Christian belief in dual-covenant theology emerged as a phenomenon following Christian reflection on how their theology influenced the Nazi Holocaust.
Secularism in Israel
The Jewish population of Israel, can be divided, albeit imperfectly, into three groups: Orthodox, Traditional, and Secular. The largest group is the Secular Jews making up 41.4% of the Jewish population, followed by the Traditional Jews accounting for 38.5% of the population, with the remaining 20% populated by the orthodox and ultra-orthodox. In Israel, the Reform and Conservative movements are estimated to make up 7.6% of the Jewish population, a significantly lower rate compared to the Jewish diaspora.