From what I understand, there are two different senses in which “children of God” is used:
- A creation of God
- An adopted son or daughter of God, making someone a brother or sister of Christ and therefore an heir with him.
I believe the former is what Paul is referencing here, that in a general sense, as creations of God, we can be called his children. But of more importance, theologically speaking, is the latter, as Paul mentions in Romans 8: “For all who are being led by the Spirit of God, these are sons of God. For you have not received a spirit of slavery leading to fear again, but you have received a spirit of adoption as sons by which we cry out, “Abba! Father!” The Spirit Himself testifies with our spirit that we are children of God, and if children, heirs also, heirs of God and fellow heirs with Christ, if indeed we suffer with Him so that we may also be glorified with Him” (Romans 8:14-17). There is a special sense in which we, as his creation, become more fully his children, with Christ as our elder brother. This is an act of love on God’s part; indeed, John says this when he states, “See how great a love the Father has bestowed on us, that we would be called children of God; and such we are” (1 John 3:1).
Greek-wise (and I say this with humility and am open to correction, because I have a limited knowledge of Koine), the word for “children” in 1 John 3:1 and Romans 8:16-17 is “tekna,” and the word for “sons” in Romans 8:14 is “huios,” different from “genos” used by Paul in Acts 17. I am not sure of all the significance that this carries, but from what I know, genos is used when speaking of physical begetting (this word is where we get “generations” or “gene”), while the other two are used in a more legal sense, where we are declared to be sons/children of God. So I do think that there is a difference.
So in the previous reply, I meant “children of God” in the special, salvific sense; Paul, at Mars Hill, refers to the general sense, that we are God’s creation. If all of humanity were God’s children, then all would be indwelt by the Spirit and would be heirs with Christ; the New Testament makes it clear that not all are saved.
Hopefully that clears things up.
Blessings,
Jay