God's children are called the remant.
Satan exerted his evil influence to draw away the majority of people to do evil. Most people do not choose to follow GOD.
In the first world, Noah and his seven family members became the remnant of the initial creation.
In the second world, GOD assigned most of the population to be under angelic rule. GOD kept a fraction of humanity for Himself to oversee: the family of Jacob—Israel.
Moses explained it this way:
7 “Remember the days of old,
Consider the years of many generations.
Ask your father, and he will tell you;
Your elders, and they will tell you:
8 When the Most High divided the nations,
When He scattered the sons of Adam,
He set the boundaries of the nations
By the number of God’s angels.
9 For the Lord’s portion became the people of Jacob;
The allotment of His inheritance is Israel.
(Deuteronomy 32:7-9 OSB)
GOD chose Israel to be His portion before Abraham was even born. GOD foreknew what He would do in the future.
The "portion" GOD chose was from all humans. This portion of GOD's people, throughout the Bible, are known as the remnant.
To understand who is being discussed by the term "the remnant," we must look at the context to see who the whole is. For instance, in Deuteronomy 32:7-9, the whole represented all of humanity—all of the nations. Later on, the whole represented the physical Israelites.
We are introduced to this concept of Israel as the remnant in Genesis 45 when Joseph revealed himself to his brothers in Egypt. It says:
4 But Joseph said to his brothers, “Come near to me.” So they came near. Then he said, “I am Joseph your brother, whom you sold into Egypt. 5 Now therefore, do not be grieved or angry with yourselves because you sold me here; for God sent me before you to save life. 6 For this is the second year of famine in the land, and five years still remain in which there will be neither plowing nor harvesting. 7 For God sent me before you to preserve you as a remnant on the earth, and to sustain you as a great remnant. 8 So now, it was not you who sent me here, but God; and He made me a father to Pharaoh, and lord of all his house, and ruler throughout all the land of Egypt.
(Genesis 45:4-8 OSB)
The term "the remnant" is mentioned throughout the Bible after this. Israel became wicked and the number of the faithful to GOD became smaller and smaller. The wicked Israelites became part of the masses of evil rather than the remnant of GOD's people.
The apostle Paul explained it to the Christians in Rome during the first century:
9:27 Isaiah cries out concerning Israel:
“Though the number of the Israelites be like the sand by the sea,
only the remnant will be saved.
28 For the Lord will carry out
his sentence on earth with speed and finality.”
29 It is just as Isaiah said previously:
“Unless the Lord Almighty
had left us descendants,
we would have become like Sodom,
we would have been like Gomorrah.”
30 What then shall we say? That the Gentiles, who did not pursue righteousness, have obtained it, a righteousness that is by faith; 31 but the people of Israel, who pursued the law as the way of righteousness, have not attained their goal. 32 Why not? Because they pursued it not by faith but as if it were by works. They stumbled over the stumbling stone. 33 As it is written:
“See, I lay in Zion a stone that causes people to stumble
and a rock that makes them fall,
and the one who believes in him will never be put to shame.”
11:1 I ask then: Did God reject his people? By no means! I am an Israelite myself, a descendant of Abraham, from the tribe of Benjamin. 2 God did not reject his people, whom he foreknew. Don’t you know what Scripture says in the passage about Elijah—how he appealed to God against Israel: 3 “Lord, they have killed your prophets and torn down your altars; I am the only one left, and they are trying to kill me”? 4 And what was God’s answer to him? “I have reserved for myself seven thousand who have not bowed the knee to Baal.” 5 So too, at the present time there is a remnant chosen by grace.
(Romans 9:27-30; 11:1-5 NIV)
There will always be a remnant of humanity who are faithful to GOD. But make no mistake, being a physical Israelite made no eternal difference for the unfaithful, for GOD rejected them. Likewise, GOD rejects those who claim the name Christian who are unfaithful.