The term Christian and Spiritual Israel are the same... The plan for God's people was laid in the garden after Adam and Eve sinned Gen 3:15... this plan included all peoples, throughout all dispensations, that accepted the atonement for their sins... in type through the animal sacrifice and in antitype through the blood of Christ. God doesn't have two groups of people, all those that believed in the promise to come or the promise given are called God's Israel.
Israel (
Hebrew: יִשְׂרָאֵל,
Standard Yisraʾel Tiberian Yiśrāʾēl; "Triumphant with God", "who prevails with God"... sounds like God's people through all time doesn't it? Call it physical Israel/spiritual Israel/Christianity/the Remnant/the Redeemed... no matter what you call it, we are all part of the same family.
You can see the results of our determined separation of God's people with Pope Francis' declaration that Jews don't need to believe in Jesus to be saved. The premise, is that they are separate from Christianity and have their own salvation through what Christ gave to them... WRONG! God's teachings for His people is progressive and all must continue in His light as He shows us the way forward to a perfect understanding of Him. There have been marked moments of increased Light given throughout time that if the church didn't follow the Lamb, they were lost. Adams instruction to his family, Noah's message to the antediluvians, Moses' message to the Hebrew slaves, Christ's message to the Jews, the Reformers message to the persecuted church, Adventism's message to the Protestants, and finally, the Latter Rain Spirit poured out upon His people just before the second coming.