Paul teaches consistently about the power of Christ to help people repent of sin and live in harmony.
“The Olive Tree and the Work of God: Jacob 5 and Romans 11,” by James E. Faulconer, in The Allegory of the Olive Tree, at Book of Mormon Central
When Paul writes about grafting branches of an olive tree, he may not be drawing directly from Zenos as Jacob did, but he is drawing on common Jewish theological literature. The way Paul and Jacob each use the symbol is significantly different, but there are commonalities too: Israel will be saved only by God, and the Lord will keep his covenants with his chosen people.
Zenos and the Texts of the Old Testament by David Rolph Seely and John W. Welch, in The Allegory of the Olive Tree, at Book of Mormon Central
In Romans 11, Paul’s symbol of the olive tree evokes Old Testament olive imagery that his audience understood. Olive symbols are found prominently in Exodus 15, Psalms 52 and 80, Hosea 14, Isaiah 5, and Jeremiah 11.
Paul's Use of the Word "Grace," by Brent J. Schmidt, from Relational Grace: The Reciprocal and Binding Covenant of Charis (published by BYU Studies)
When Paul writes “grace,” as he does in Romans 11, he invokes the social system in which a benefactor gives something of value to another, and the receiver is obligated to give thanks, service, allegiance, and lesser value back to the benefactor. Scholars beginning in the fifth century changed the meaning of this word to mean something given with nothing required in return, but this is not what Paul and other NT authors intended.
"The Occasional Nature, Composition and Structure of Paul's Letters," by Eric D. Huntsman, in How the New Testament Came to Be: The Thirty-fifth Annual Sidney B. Sperry Symposium
“Paul often structured his letters according to the principles of Classical rhetoric.... This frequent two-fold division into indicative and imperative sections is important because many commentators focus on Paul’s doctrinal teaching without sufficiently noting that almost every letter also discussed how the reality of the message of Christ should affect how Saints should live as Christians. For instance, the weighty doctrinal section of Romans (1:16–11:36) is followed by a shorter but still significant imperative or hortatory section (12:1–15:13) that includes important discussions of Christian ethics (12:1–13:14) and relations between the strong and the weak (14:1–15:13).”.
A Note on Romans 12:20, by BYU Studies staff
When Paul teaches in Romans 12 that Christians must be kind even to their enemies, he writes, “If thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head.” He quotes Proverbs 25:20-21 and likely means that acts of kindness given to evil people put them to shame and evoke God’s vengeance. He may also hint that these burning coals might stir within an enemy a desire to repent.