perry,
you are correct that its the heirs of the convenant who are God's sons and daughters. Those chosen who are faithful to him and his son and are set aside by God. But for what? To be co-heirs with Christ. This time we live in (gospel age) is for the choosing of those who will reign 1,000 years with Christ - this is one important thing that Charles Russell got right but Rutherford changed his views on it.
Of all the rest of mankind - once the kingdom is ruling, they will have their eyes opened to truth and there hearts will be turned to God and they will have the opportunity to choose to accept Christ sacrifice on thier behalf. Right now only some have their "spiritual" eyes opened to accept Christ - The Church.
The bible says God PUT the nation of Isreal into spiritual darkness. If he did, then how can he destroy them for not believing his son is the Messiah? That would not be loving nor just. God is love and we have to recogncile the whole bible together.
All the ancient prophets fortold the ressurection of the righteous (believers) and unrighteous (non-believers) and that the non-believers go thru a judgement time but nowhere is there a mass destruction mentioned in the Bible. A loving God would not destroy people who are living in this unjust world, dealing with imperfections, have had their spiritual eyes blinded, ect. for not believing in him. Only once these obstacles are removed will ALL have opportunity to accept Christ's sacrifice for them. Only the Church (Christ's Body) is being set aside now for the purpose of reigning with the Lord. No other people are being dealt with now in this time.
When "we" in the Church (believers) partake of the bread and wine, we are essentially asking Jesus to cover our sins now in this time period as we are accepting his sacrifice for our covering during this time. His sacrifice does not yet cover any outside the convenant. But it is also why if we turn away from Christ after this, we have no more covering for our sins left.
In the OT it prophesised that not only will all people in modern times be brought back and taught about God but so will the ancient nations of Sodom, Gemmorah, Tyre, Sidon, Egypt and all the others that the Isrealites killed off. Some say God was cruel to allow this but he promises to bring them all back in the future. There are ample texts in the OT that speak about this and Jesus himself spoke about Sodom and Gemmorah being alive again during the "judgement day".
If you would like to talk more about the points you made and the ones I am making here, please pm me. Thanks, Lilly