received … apostleship: The apostle Paul might be referring to both himself and the other apostles, or he might be using "we" to only refer to himself.
we received grace and apostleship: Paul always makes it evident that his unique authority is a gift from God (see also 15:15–16).
to the obedience that comes from faith: This summarizes Paul’s goal in preaching to Gentiles (non-Jews). It frames the book of Romans, as he repeats the idea in different words at the end of the letter (16:26). Paul wanted Gentiles to trust in Jesus Christ. He emphasized that trusting in Jesus Christ as the Lord means committing to obey him. Faith and obeying are not the same, but one does not happen without the other.