"The Bible speaks of salvation is in terms of adoption into God’s family.
"The focus of salvation as adoption relates to our legal status in God’s family.
"We hear this emphasis in our reading about saving faith in Christ in John 1:12,
“As many as received Him, to them He gave the right to become children of God to those who believe in His name.”
"By adoption, we understand that a legal right has been granted us. As Christians we not only possess the renewed nature of a child of God but also legal standing as an heir.
"Being children of God by adoption is also found in Romans 8:16–17,
“The Spirit Himself bears witness with our spirit that we are children of God, and if children, then heirs — heirs of God and joint heirs with Christ.”
Joint heirs.
"People living in the Roman world would likely have been familiar with Roman regulations concerning adopted sons.
"Since by adoption God has made believers His children with full legal standing, we are joint heirs with Christ.
" Ancient Roman adoption laws furnished a good illustration of the permanence of a believer’s place in God’s family.
"If a Roman father did not have a biological son and chose to adopt a boy as his son, that adopted son had all the legal standing in the family as a natural born son would have.
"Quite often the adopted son was from a slave family. Adoption immediately lifted the adopted son out of the ranks of slavery and gave him social standing.
"More than that, Roman adoption law provided that an adopted son could not be disowned, having been freely screened and chosen by the adoptive parents.
"Furthermore, an adopted son not only had new status but also had full legal rights to the family inheritance.
Part of the family.
"The most complete statement of adoption is Galatians 4:4–7,
“When the fullness of the time had come, God sent forth His Son, born of a woman, born under the law, to redeem those who were under the law, that we might receive the adoption as sons.
"And because you are sons, … therefore you are no longer a slave but a son, and if a son, then an heir of God through Christ.”
"Membership in the family of God will be brought to completion when the spiritual membership also becomes a physical one upon being given a resurrection body like unto Christ’s resurrection body.
"Philippians 3:20–21a puts it like this:
“Our citizenship is in heaven, from which we also eagerly wait for the Savior, the Lord Jesus Christ, who will transform our lowly body that it may be conformed to His glorious body.”
You seem to be quoting people and not answering questions.
"The Bible speaks of salvation is in terms of adoption into God’s family." - Salvation is completed in three phases, 1. Justification, 2. Sanctification, 3. Glorification. Please specify which phase you are referring to.
"The focus of salvation as adoption relates to our legal status in God’s family." - are you not a legal child by the new birth already - in ancient Rome it was not uncommon to adopt your biological child into a new position in the family as the only person that could do the adopting was the Pater Familius - the Father of the Family, or the head of the family, which was the oldest male in the family
"We hear this emphasis in our reading about saving faith in Christ in John 1:12," - Here we are told that we have the power (exusia)
to become the sons of God. I do believe that this applies to the adoption - We currently have been granted the right to be revealed as the Sons of God at the adoption - We are currently the Child of God by birth and are referred to as children when we behave childishly and as sons when we behave maturely
“As many as received Him, to them He gave the right to become children of God to those who believe in His name.” - If I did anything at Justification (other than believe), then grace is not grace
"By adoption, we understand that a legal right has been granted us. As Christians we not only possess the renewed nature of a child of God but also legal standing as an heir." - in Galations, the child is heir of all, but not yet adopted
"Being children of God by adoption is also found in Romans 8:16–17," - I addressed these in my question - please respond to the question asked
“The Spirit Himself bears witness with our spirit that we are children of God, and if children, then heirs — heirs of God and joint heirs with Christ.” - you are assuming that this verse is due to the fact that you are adopted - you have not proved this assumption.
"People living in the Roman world would likely have been familiar with Roman regulations concerning adopted sons." - I am very familiar with the Roman regulations - you had to be a male, free, citizen of Rome - therefore at the moment of justification / new birth, you did not qualify
"Since by adoption God has made believers His children with full legal standing, we are joint heirs with Christ." - Galations refers to unadopted children as heirs - therefore, please prove the assumption of this statement which is that children are not heirs until they are adopted
" Ancient Roman adoption laws furnished a good illustration of the permanence of a believer’s place in God’s family." - I agree
"If a Roman father did not have a biological son and chose to adopt a boy as his son, that adopted son had all the legal standing in the family as a natural born son would have." - That is true - however, since the Pater Familius could move people from grandson to any other position in the family by adoption also, it does not prove your point
"Quite often the adopted son was from a slave family. Adoption immediately lifted the adopted son out of the ranks of slavery and gave him social standing." - This statement only includes the starting point and ending point of this process - The truth is that a slave could be given the greatest reward possible, which was his freedom, with the added gift of citizenship (if this was not added, he was not eligible), then he could be adopted. A slave was not even allowed in the building that had the judgement seat where adoption occurred.
"More than that, Roman adoption law provided that an adopted son could not be disowned, having been freely screened and chosen by the adoptive parents." - does not prove the point of when adoption occurs
"Furthermore, an adopted son not only had new status but also had full legal rights to the family inheritance." - so do the children born in the house - how is this not a benefit of the new birth also.
"The most complete statement of adoption is Galatians 4:4–7" - this is addressed in my question, please address the question
“When the fullness of the time had come, God sent forth His Son, born of a woman, born under the law, to redeem those who were under the law, that we might receive the adoption as sons." - "Might receive" is in the subjunctive mood, in other words it does not address the when of adoption as mentioned in the question.
"And because you are sons, … therefore you are no longer a slave but a son, and if a son, then an heir of God through Christ.” - you leave out the fact that the child was also waiting for the adoption, and fail to address the question, which was about the "and" being the Greek word "de" and not "kai" and, therefore, the statement in 4:6 is distinct from, and does not build on, the statement in verse 5. This is why Bibles that are written in Paragraph form place verse 6 in a new paragraph.
"Membership in the family of God will be brought to completion when the spiritual membership also becomes a physical one upon being given a resurrection body like unto Christ’s resurrection body." - you have just stated when I am currently believing adoption to occur, and only to occur.
"Philippians 3:20–21a puts it like this:
“Our citizenship is in heaven, from which we also eagerly wait for the Savior, the Lord Jesus Christ, who will transform our lowly body that it may be conformed to His glorious body.” - This statement did not address when the adoption occurs.
I have been studying this for over a year, maybe two. If it could be answered with simple quotes, I would have long since been satisfied.
