Are Paul's writings still the words of Jesus?
Yes. The apostle Paul makes it plain that everything he writes he received from the Lord in glory, so his writings are still the words of Jesus. They are now post-resurrection and most appropriate because Jesus has finished the work of the cross.
Les explains that everything Jesus said in His earthly ministry was before the cross—He hadn't died yet, His blood hadn't been shed. Then when you get to the apostle Paul, Paul makes it plain that everything he writes he received from the Lord in glory. So it is still the words of Jesus, but now in the most appropriate time: post-resurrection, after He finished the work of the cross. Les says he stands by his guns that we must adhere to Paul's writings, because that is where the meat of our doctrine lies.