Why does Paul quote Scripture to tell Gentiles to 'rejoice'?
Paul is weaving together Old Testament promises to show how God's plan always included the Gentiles.
From Exclusion to Inclusion
He quotes Deuteronomy 32:43 (using the Greek translation called the Septuagint) which says, 'Rejoice, O Gentiles, with his people.' This isn't just a casual invitation; it's a fulfillment of ancient prophecy.
The Root of the Joy
This shared joy stems from God's faithfulness. The Gentiles, who were once considered outsiders, are now invited to celebrate with God's chosen people, Israel. This unity in Christ is a profound testament to God's inclusive heart.