Does the Bible speak of God having TWO peoples; Israel and the Church? Let’s test that.
First we will ask if a new group was ever foretold by the prophets.
“For the Lord God does nothing without revealing his secret to his servants the prophets.” (Amos 3:7)
The prophets don’t ever mention a future group that would replace or coexist with Israel as God’s people. It’s not there.
Jesus didn’t appear to be aware of a new, separate body of believers either. Rather, he said, “…there will be one flock…”
“He answered, “I was sent only to the lost sheep of the house of Israel.” (Matthew 15:24)
“I am the good shepherd. I know my own and my own know me, just as the Father knows me and I know the Father; and I lay down my life for the sheep. And I have other sheep that are not of this fold. I must bring them also, and they will listen to my voice. So there will be one flock, one shepherd.” (John 10:14-16)
Even Ciaphas prophesied of all the children of God being gathered into one.
“But one of them, Caiaphas, who was high priest that year, said to them, “You know nothing at all. Nor do you understand that it is better for you that one man should die for the people, not that the whole nation should perish.” He did not say this of his own accord, but being high priest that year he prophesied that Jesus would die for the nation, and not for the nation only, but also to gather into one the children of God who are scattered abroad.” (John 11:49-52)
In the 3rd century BC, a group of 72 scholars translated the Hebrew Scriptures (Old Testament) into Greek. This translation is known as the Septuagint or LXX. This is the work quoted by New Testament writers whenever they quoted scripture.
In the Septuagint, a handful of Hebrew words meaning assembly or congregation were translated to the Greek word ekklēsia [ἐκκλησίᾳ, Strongs 1577] and its variations.
To get a better sense of how to understand the meaning of ekklēsia in the LXX, I created a spreadsheet that lists every instance. (View the spreadsheet here). Out of 268 renderings of Hebrew words to ekklēsia, 225 refer to Israel. Put another way, in the old testament Greek translation available at the time of Jesus and the apostles, ekklēsia referred to Israel 84% of the time. The other times, it could mean any kind of assembly, including an enemy army (Ezekiel 26:7) or swarm of bees (Judges 14:8).
Thus, when we encounter ekklēsia many times in the New Testament, there is immediate continuity established by 225 previous uses in the Old Testament. There is at least an 84% chance the intended meaning is God’s people and not a swarm of bees.
In Acts, the word ekklēsia was used to describe the congregation of Israel, just like in the Old Testament.
“This is the one who was in the congregation [ekklēsia] in the wilderness with the angel who spoke to him at Mount Sinai, and with our fathers. He received living oracles to give to us.” (Acts 7:38)
Yet, the most common modern English translation of ekklēsia in the New Testament is church. Unfortunately, the translation of ekklēsia to church has led many to assume a new body of believers came into being that is distinct from Israel. This assumption is heavily challenged by the 225 uses of ekklēsia to mean the assembly or congregation of Israel in the Septuagint.
At no time in the Bible does God’s people exclude Israel. When the entire Bible is read in Greek, ekklēsia is a description of God’s people from Genesis to Revelation.