Unfortunately, bringing Eph 1:3-23 to bear upon Rom 9 does not harmonize with Rom 9:16, which clearly teaches that man's will is not involved in God's sovereign decrees of election.
And I categorically reject the heresy that God is merely a potential savior! God actually SAVES all those whom he has predestined (also cf. Rom 8:28-30). He saved Issac and Jacob in Rom 9 by decreeing that they would participate in his covenant promises to Abraham, didn't he? But God also predestined that Ishmael and Esau would not participate in those covenant promises, so they remained the earthly, natural children of Abraham according to only the flesh.
Also, to be "in Christ" or "in Him" is precisely to be no longer in Adam since we're in the Last Adam. Don't forget: God ordained Adam to be the Federal Head of the entire human race; whereas the Last Adam is the Federal Head of all the Father has given to Him. Once a believer is in the Last Adam, he is no longer in the original Adam who is a type of Christ by contrasts.
As far as Deut 30:19 goes that command denotes man's moral responsibility which he cannot execute since [spiritual] LIFE is found only in the Lord per the text. Obviously, the spiritually dead have no ability to obey since all human beings come into this world SEPARATED from the Life of God, which is how everyone is spiritually dead! Death always logically presupposes antecedent life.
Okay, we can discuss RM 8:28-30 if you will explain how your interpretation affirms that God is all-loving per 1TM 2:3-4.
Isaac and Jacob in RM 9 merely refers to the human/natural ancestry of Christ, stating that it is not the natural descendants who are God's children. According to Paul in RM 2:28-29 & 4:9-12, not only Ishmael and Esau but also descendants of Isaac who are not spiritually circumcised by faith are not God's children.
Regarding Adam, Paul said in 1CR 15:22, "For as in Adam all die, so in Christ all will be made alive", with "all" meaning "those who belong to him" per v.23, which would be the elect, but it does not say whether they become elect by God forcing them to believe or they choose to believe and thereby become chosen.
Other Scriptures that relate to the topic of election include the following:
RM 3:9-18 says that all humanity are sinners or bent on sinning instead of following God’s law through which we become aware of sin, but it does NOT say, man is incapable of believing in Jesus and the Gospel, because the disobedience of Adam and Eve caused all humans to be born with an inherited sin nature and thus having a saving faith is against their very nature.
2TM 2:26 says that all unsaved humans are captive prisoners of Satan, bent on doing whatever he wants them to do, and LK 4:18 says that Jesus came to set the captives of Satan free.
ACTS 16:14 says that God opened Lydia’s heart so she could respond to Paul’s message, and surely everyone else needs God’s grace also, and JN 3:16 indicates that God gives everyone the grace to believe in Jesus and have saving faith.
JN 15:16 reports Jesus saying “You did not choose Me, but I chose you to bear fruit that will last.” MT 1:16 records Jesus choosing to call Simon, Andrew, James and John to follow him as disciples.
RM 9:11-16 says that God’s purpose in election is for salvation not to be by means of works or human effort but by God having mercy on whom He wants or chooses.
God wants all to be saved per 1TM 2:3-4, but apparently some, many and even most people reject His calling (MT 22:14).
2PT 3:9 says that God is not willing that any should perish, but wants everyone to repent, but 2THS 2:10 says some perish because they refused to love the truth and be saved.
RM 9:22-23 indicates that God could have chosen to condemn everyone to show his power, but some are shown mercy, presumably those who did NOT refuse to love the truth.
Those not chosen or shown mercy are given the justice they deserve, but the elect are saved as long as they persevere in loving the truth or having faith in Christ.
