Those who are born again by faith in Jesus Christ, will be declared to be sons of God, at the resurrection of the dead, on the last Day At His coming.
At the resurrection of the dead in Christ, those who are His will have become sons of God and be at that time, as equal to the angels.
So it will be at the resurrection when the sons of God will be manifest in reality.
For now, those who have faith in Jesus Christ, for salvation, have the hope of becoming sons of God.
12 But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name: John 1:12
Those who are sons of God, "by faith" will obtain literal sonship when they are resurrected from the dead.
Until then we have the hope of salvation, that is to say, the hope of becoming sons of God, through faith in Jesus Christ.
19 For the earnest expectation of the creature waiteth for the manifestation of the sons of God. Romans 8:19 KJV
For Now we eagerly wait for it with perseverance.
23 And not only they, but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, to wit, the redemption of our body.
24 For we are saved by hope: but hope that is seen is not hope: for what a man seeth, why doth he yet hope for?
25 But if we hope for that we see not, then do we with patience wait for it.
Romans 8:23-25 KJV
No one becomes a son of God through natural child birth.
Before Christ, only angels were referred to as sons of God.
Adam was created by God Himself.
Jesus is the only Begotten of the Father.
JLB