In the Old Testament God promised Israel a new covenant between Himself and the nation after establishing the covenant with them at Mt Sinai. This new covenant would be different in that God putting His spirit in them and more. Jesus, declared this new covenant with his Apostles when he took the cup and declared it to be the new covenant in His blood. Israel, as a nation, rejected the covenant but many did receive it and God indeed put His Spirit in them. Afterwards the non-Jews or gentiles also partook of this new covenant. However this new covenant with the Jews will be fulfilled at the conclusion of the great tribulation period.