Just to point out how incompatible sinners are to God, they have to die through baptism, and be born again in Christ (who had to die for the sins of the world) becoming a "new creation" just be made compatible with God (Eph. 1:3-6). Without the Gospel of Christ, sinners are not only incompatible with God, but simply unacceptable to God.

Therefore, this simply straight up ignorant notion that many in the world have that "everyone" is God's children, is beyond foolishness, and a presupposition based on nothing!

It is only through the power of God's Gospel that those who receive the Lord Jesus as their Lord and Savior, are given the right, by God, to be called children of God (John 1:12-13). And this is NOT of the will of the flesh, or the will of man, it is the will and gift of God (Eph. 2:8-9).

This is why the Bible states, unequivocally, that if one denies the Son (Jesus), they've denied the Father who sent Him also. And if one has not the Son, they've not the Father also. (1 John 2:23; John 15:23)

There are many people out there who reject the Son of God; denying both His Lordship, and His role in the Godhead as Savior of mankind. Yet, these same individuals like to say that they, as well as all people in the world, are children of God. But again, this is categorically—and more importantly—biblically wrong!

God is surely the "Creator" of all, but not the Father of all! He is Lord over all, but only to those whom He has predestined for adoption as sons, by the conforming of them to the image of the likeness of His Beloved Son, is He Father.