Even so then at this present time also there is a remnant according to the election of grace. Romans 11:5
Notwithstanding Israel's failure as a nation, there remained among them a goodly remnant of such as should be saved. At the time of the Saviour's advent there were faithful men and women who had received with gladness the message of John the Baptist, and had thus been led to study anew the prophecies concerning the Messiah. When the early Christian church was founded, it was composed of these faithful Jews who recognized Jesus of Nazareth as the one for whose advent they had been longing. It is to this remnant that Paul refers when he writes, "If the first fruit be holy, the lump is also holy: and if the root be holy, so are the branches."
Paul likens the remnant in Israel to a noble olive tree, some of whose branches have been broken off. He compares the Gentiles to branches from a wild olive tree, grafted into the parent stock. If some of the branches be broken off, he writes to the Gentile believers, and thou, being a wild olive tree, wert grafted in among them, and with them partakest of the root and fatness of the olive tree; boast not against the branches. (The Acts of the Apostles, 376)
Reflection: God has always had a faithful remnant. With the believing Jews, the remnant, God was able to graft in the believing Gentiles.