First, we must remember, of course, that many of Paul’s letters were written before most of the Gospels and Acts were composed – so he could hardly quote books not yet written. But Paul could and did quote sayings of Jesus that were already recorded or held in memory by the disciples and other early Christians. For example, in 1 Corinthians 11:22-24 the apostle clearly quotes Jesus’ words from the Last Supper, and these sayings are also found in Luke’s later account of the event (Luke 22:19-20). Clearly, both Paul and Luke were relying on words of Jesus from that event that had been preserved by those who heard them.
There are a few other examples like this where Paul appears to quote things said by Jesus during his ministry. In 1 Corinthians 8:6 Paul seems to quote words later recorded in the Gospel of John (John 17:3), and in 1 Timothy 5:18 Paul uses an expression of Jesus – “the worker deserves his wages” – recorded by Luke (Luke 10:7), though Paul could possibly be summarizing one or more Old Testament scriptures on this topic (Deuteronomy 25:4, Leviticus 19:13, etc.).
But are these few direct quotations from Jesus’ teachings all that we can find in Paul’s writings? The answer is a decisive “no” – but we have to look carefully for evidence that is easily read over. Where we do find Paul almost constantly quoting Jesus is in small expressions found in the parables recorded in the Gospels.
Jesus told his disciples that his parables were given to teach them, but to hide the truth from “those on the outside” or “them that are without,” as the King James Version puts it (Mark 4:11). Interestingly, Paul uses this exact expression five times in his writing (1 Corinthians 5:12, etc.), clearly following Jesus in referring in the same way to those who do not understand God’s truth. In the opposite situation, Paul refers to those who do know God as the “children of the light” (1 Thessalonians 5:5, etc.), using an expression of Jesus recorded in Luke 16:8.
When we turn to the parables themselves, we find example after example of Paul using the expressions of Jesus – clearly from parables that Paul must have heard and memorized. Some of those parables were doubtless the apostle’s favorites because he uses expressions from them or makes allusions to them frequently. Take, for example, Jesus’ parable given so that “they ought always to pray and not lose heart” (Luke 18:1 ESV). Paul uses the same word and expression in 2 Thessalonians 3:13 when he writes “do not grow weary in doing good” – and the “doing good” that Paul is speaking of in context specifically includes prayer and perseverance (2 Thessalonians 3:1, 5) – themes he repeats often.
The various parables regarding the sower and the seed, the different types of ground the seed falls upon, as well as the “tares” or weed seeds that are mixed in the crop are all reflected directly or indirectly in Paul’s writings. For example, Paul characterized those who perverted or attacked the truth (as in Acts 13:10) with the same term, “sons of the evil one,” used by Jesus in the parable of the tares (Matthew 13:28 ESV).
Just as Matthew 13:22 states that riches can choke a person's spiritual development, Paul warns us that those who want to be rich are drowned by their desire for riches (1 Timothy 6:9). Conversely, just as Jesus spoke of the good ground that brings forth much fruit (Matthew 13:23), Paul encourages the Romans to be persistent in fruit-bearing (Romans 2:7) and praises the Colossians for this (Colossians 1:6).
Paul also takes expressions from the parables in describing his own ministry and work. In 1 Thessalonians 2:2 he states that he was “shamefully treated” in Philippi – using exactly the same expression found in the parable of the king whose servants were “shamefully treated” by the tenants of his vineyard (Matthew 22:6).
But perhaps nowhere do we see more connections between Paul’s writings and the sayings of Jesus than in the final parables Jesus gave at the end of his ministry. Ephesians 5:32, for example, is based on an analogy Paul does not feel he need explain – that of Christ as the bridegroom – because it was already made by Jesus himself (Matthew 25:1). In the same way, Paul alludes to the spiritual application of the parable of the talents (Matthew 25:14-30) not once, but three times: in Romans 12:6, 1 Corinthians 12:11, and Ephesians 4:7.
In all these examples and a great many more, we find ample evidence that far from ignoring the teachings of Jesus, Paul was steeped in them, had them in his mind whenever he wrote his epistles, and alluded to them constantly.