The importance in framing it as a conversion or call rests in the degree to which Paul still has a foot in Judaism. Framing it as a call would lean toward the side that Paul was called to the Gentiles and largely still identifies as Jewish (more like a modern messianic Jew). Passages like in Acts 15 where believers were in the sect of pharisees supports this view of still being in judaism. A conversion would be more of a complete change from Judaism to Christianity (though the early movement was not called this).
Paul’s identification as a Pharisee raises questions about his persecution in how the Pharisees were not the group that had the power to arrest someone and lock them up (the sadducess would have more been able to do this). The Pharisees were not in the Temple but in synagogues and would have had less power. IT also seems that the Pharisees were not hostile to Christians, as there are places where believers are referred to as still being pharisees (Acts 15) and Gamaliel, a pharisee leader, is described as being against the killing of Christians.
Sanders is referring to the relatively new idea that Israel did not believe that in order to be in God’s people you must follow the laws and commandments set forth in Torah (that being the only criteria) but rather that if you were an Israelite you were in the people of God by default and that the only way for you to get out of the people of God was for you to willingly not try to reconcile your sins through any of the rituals and sacrifices ascribed in Torah (like tax collectors and prostitutes might do). Thus, gentiles (not being Israelites) were out of the people of God by default, not just because they didn’t have Torah and didn’t follow the commandments (old view).
At least a sizeable portion of Paul’s church in Cornith did not think there would be a resurrection of the dead (that once you died you were just dead), since Paul decided to specifically mention some people not believing in 1 Cor 15. This belief was probably because the Cornith church was well-off financially and didn’t want a better life in the future. Paul goes on to describe the resurrection being much better than the current life (Paul places emphasis on that) and likens it to a plant, going in as a mere seed but coming out as a new thing (old and new creation). Paul says that the resurrection body will have power over death (won’t die) and be imperishable.
The circumcision faction argued that the new Gentile converts to Christianity should follow three defining characteristics of what separated Jews from Gentiles: sabbath laws, dietary restrictions, and circumcision. These were under the Abrahamic covenant that was interpreted for a long time to have no wiggle room as far as circumcision went for Israelites (that if you were in the people of God you were to be circumcised). However, Paul refers to “to your descendants” in Gen 15 as meaning all of Ishmael’s descendants (not in the people of God) too, and that Abraham really wasn’t righteoused by his actions but by his faith in God and the promises he had for him (specifically in the promise of Christ). Therefore, Paul thought that the gentiles need not heed the circumcision, sabbath, and dietary laws as it caused unjust division among Christians (Paul said that it was nonessential).
Now the promises were made to Abraham and to his offspring; it does not say, “And to offsprings,” as of many; but it says, “And to your offspring,” that is, to one person, who is Christ.
Paul uses the hebrew term for offspring and plays on its ambiguity (something that ancient interpreters often enjoyed because it added to the mystical nature of God- inspired texts). The word itself is singular but was traditionally interpreted to reference the collective (many offspring), but Paul is using his liberty as an Apostle and as a witness to the resurrected Jesus to make a bold claim that this is referring to the singular Messiah, Jesus. He connects this to his larger point that Abraham was righteoused (from reckoned it to him as righteousness) by faith (not in his works, in his obedience to God) and that it was his belief in the promise of Jesus (singular) that earned him this reckoning.
Paul uses the slave metaphor as a way of separating two distinct domains that he sets up throughout Romans 6-8, where one domain involves being under the control of (being a slave to) sin and the other domain involving being under the power of God and righteousness. Paul’s language even implies this sinful nature as being a physical part of people before they are saved. The phrase “when you were free in regard to righteousness” does not mean that they were free to be righteous. Instead it means that you were not under righteousness’ (God’s) control. The last sentence sounds like ethical behavior is being talked about (the wages of sin is death), but in light of the preceding sentence it is likely referring to more of a domain switch, that being under the control of (working for and getting paid by) sin leads to death.
Paul is talking to the Gentiles, people that did not have a thousand year history of rewriting and copying parts of Torah and had an established priestly class of people ot read them the Torah texts, to the idea of atonement probably was not Paul’s favorite idea to expound upon because it did not reflect accurately the situation the Gentiles were to be in if they chose to be a Christian (they wouldn’t know what specifically they did wrong, what legal wrongs the committed, that Jesus paid for). So, Paul gravitates towards a participation in Christ’s death, being a old creation in your old life and switching domains to a new life under the domain of righteousness, because this would have been more sensible to Gentiles and it would have emphasized the benefits of moving to a new religion (being a new creation) to people that weren’t convinced that they needed a new religion and way of doing things (since Paul was often talking to well-to-do greeks and people content with their old pagan religions).
The use of Lord for Jesus and God the Father for God seems to suggest a distinction between the two, that they were not the same person (a trinitarian view). However, there are places in the new testament (like Phillipians 2:6-11) that suggest a worship of Jesus. If early Christians had a low Christology, meaning that they emphasized the human nature of Jesus, then this worship would be odd. However, many Jews (who hated polytheism) are shown to have joined the Christian movement, therefore to solve these problems, it is suggested that Jesus was thought of as a divine chief intermediator (like and angel), as close to God as possible but without actually being him. This would allow for a high Christology among Jewish believers and explain the worship, and it would also explain the instances where the language sounds like Jesus is the conduit for God’s power.
The term faith of Jesus is ambiguous because in the original language it is written it can be interpreted two ways, as a possessive or genitive. One way of interpreting (the way in translations is often chosen based on context) is that it is someone’s faith in Jesus, emphasizing the God-like nature in Jesus. The other way, however, is to interpret it as Jesus’ faithfulness, as in the perfect life Jesus led. The importance of the distinction is that in Romans 3 21-22 the issue of whether you are righteoused by your faith in Jesus (emphasizes a high Christology) or you are righteoused by Jesus’ faithfulness (a low Christology) can come up.