Let's say the neighborhood kids come over to my house. Everyone there I have authority over because I own the property. But only my kids are my people because we have an intimate relationship.
In creation all people belong to God. Not everyone are in an intimate relationship with Him.
The Jewish nation is a good example. While all people in all nations belonged to God by virtue of creation, not all nations were in an intimate relationship with God. Israel was particularly called the people of God. They were His chosen people. Likewise, in 1 Peter 2:9, saved people are called a peculiar and chosen people.
In creation all people belong to God. Not everyone are in an intimate relationship with Him.
The Jewish nation is a good example. While all people in all nations belonged to God by virtue of creation, not all nations were in an intimate relationship with God. Israel was particularly called the people of God. They were His chosen people. Likewise, in 1 Peter 2:9, saved people are called a peculiar and chosen people.
Deut. 32:36 “For the LORD will judge His people (all the inhabitants of the earth). And He will have compassion on His servants (the church), when He sees that their (the church's) power is gone, And there is no one remaining, bond or free.
Heb. 10:29 How much more severely do you think someone deserves to be punished who has trampled the Son of God underfoot, who has treated as an unholy thing the blood of the covenant that sanctified them, and who has insulted the Spirit of grace? 30 For we know him who said, “It is mine to avenge; I will repay,”[a] and again, “The Lord will judge his people (all the people of the earth).”[b] 31 It is a dreadful thing to fall into the hands of the living God.
John 5:21–25. For as the Father raises the dead and gives them life, so also the Son gives life to whom he will. For the Father judges no one, but has given all judgment to the Son (judgment of all the peoples of the earth), that all (all people of the earth) may honor the Son, just as they honor the Father.
You need to separate verses into "His people" meaning sometimes the elect, and "His people" sometimes meaning all people, so that you can sort them according to where they need to fit to keep your leaky boat afloat. From a self-centred self-important "elect" human beings point of view, "My people" is limited to the group the self-important human being belongs to. From the all-loving God's point of view, "My people" is all the people of the earth.