Because today we use Jews and Hebrews interchangeably.
On the one hand there might be a degree of truth in that statement, but overall, it might cause one to lump the entire offspring of Israel into the Jewish pot which is far from the truth. There were 12 Tribes each with a name, Ten are considered lost. The return of the lost Ten Tribes is one of the crowning events of the last days. Not to mention Jews are mostly not Christian, and the Children of Israel were the true believers that is how and why they are the Covenant people. Abraham was a believer and taught his offspring. Like all of us, they could choose for themselves and ultimately chose apostasy over remaining in the fold. For as long as it lasts, these are the days of the Gentiles, but ultimately the twelve tribes will again resume their earlier status as the chosen and covenant people.