Paul’s theology developed in large part due to charismatic exegesis, i.e., Spirit-inspired interpretations and proclamations of Israel’s sacred Scripture. For the apostle the gospel of Christ fulfills God’s promises to Israel. The death, burial and resurrection of Jesus are “according to Scripture” (1 Cor 15:3-8). This does not mean that the OT predicts the death, burial and resurrection of the Messiah. It does mean that Paul finds the story of Jesus a compelling climax to God’s covenant with his people. In this sense all of Scripture finds it focus in the man from Nazareth.
Paul is a man immersed in Scripture. He speaks its language. He thinks, hopes and imagines in its symbols. He writes his letters with it resonating in his ear. Like a tuning fork it provides for him pitch, even as he produces the timbre. He situates his discourses within the symbolic world created by Israel’s sacred texts. But already these Scriptures are awash in intertextuality with fragments of earlier stories echoing in the later chambers of sacred words and promises. Paul continues the intertextual practices of his ancestors in faith, extending Scripture beyond their day to his own, finding its fullness in the Lord Jesus Christ.
Paul’s considered the Scriptures “holy” and prophetic (Rom 1:2). They are the oracles of God entrusted to Israel (Rom 3:1-2). He proclaims that all Scripture is God-breathed and beneficial for teaching, reproof, correction and training in righteousness (2 Tim 3:16). He appeals to Scripture at key moments as the final word (Galatians 3-4). When God speaks, that settles the matter.
When writing to his churches, Paul used the OT in three ways: (1) quotations, (2) allusions and (3) appropriations of theological themes. Some of these are intentional; others appear to be unintentional. But this is what you would expect from someone steeped in Scripture. Although it is not possible to distinguish accurately between a quotation and an allusion, most scholars have concluded that Paul cites the OT approximately ninety to one hundred times in his extant letters. He quotes from sixteen books altogether, but mostly from the Pentateuch, Psalms and Isaiah. The majority of his citations are found in Romans, 1 and 2 Corinthians and Galatians. Allusions to Scripture are more numerous; sometimes just a few words can conjure up the appropriate biblical image for Paul to make his point. There are some letters without explicit citations; still one finds echoes of scriptural themes and appropriations of biblical imagery in nearly all the apostles correspondence.