SirP said
Is the circumcision issue actually absent in the Gospels? If so, what are the implications for viewing the Gospels as influenced by Pauline Christianity? 

I’ve been wondering about that. Here are some thoughts. 

In Luke-Acts, where John and Jesus are both circumcised on the 8th day (as Paul claims happened to him), there is also the Jerusalem conference where the issue of a requirement of Gentile circumcision was decided with Paul present, and with a speeches by Peter and James (the blood brother of Jesus, who Paul met with, according to Galatians). So there is an issue in Luke’s account, and it not only involves Paul but touches on elements found in his writings. The details in Luke-Acts are so rich that it seems obvious that the author was working from sources other than Paul; nevertheless, the influence of Paul may be present, both in the making circumcision of issue of contention and in emphasizing that Jesus was circumcised on the eighth day with sacrifices made (ie, what Paul calls “works of the law).

Gal. 2:16 is key text worth reading closely for consideration of relationship between Paul’s writings and the life and times of Jesus as portrayed in the Gospels:

εἰδότες δὲ ὅτι οὐ δικαιοῦται ἄνθρωπος ἐξ ἔργων νόμου ἐὰν μὴ διὰ πίστεως Χριστοῦ Ἰησοῦ, καὶ ἡμεῖς εἰς Χριστὸν Ἰησοῦν ἐπιστεύσαμεν, ἵνα δικαιωθῶμεν ἐκ πίστεως Χριστοῦ καὶ οὐκ ἐξ ἔργων νόμου, ὅτι ἐξ ἔργων νόμου οὐ δικαιωθήσεται πᾶσα σάρξ.

Standard translations leave no room for the path of “works of the law” as seen in Luke

¹⁶ yet we know that a person is justified not by the works of the law but through faith in Jesus Christ. And we have come to believe in Christ Jesus, so that we might be justified by faith in Christ, and not by doing the works of the law, because no one will be justified by the works of the law. NRSV

Alternatively, it could be translated like this:

¹⁶ yet we know that a person is justified not by the works of the law, except through faithfulness of Jesus Christ. And we have come to believe in Christ Jesus, so that we might be justified by the faith of Christ, and not by doing the works of the law, because all flesh will not be justified by the works of the law.

In this reading,

1. Paul is acknowledging an earlier proclamation to people who were born and raised doing works of the law: “…except through the faithfulness of Jesus Christ, no person is justified by works of the law.” (see James Dunn, and Doug Campbell)

2. However, because not “all flesh” will become Jewish, Paul preached a path of righteousness by “the faith of Christ” alone. ** you do not have permission to see this link **

In such re-reading, Paul was allowing for a legit path of “works of the law”+”faith of Christ” for some “flesh”. In Jerome’s commentary on this passage in Galatians, he said, Paul was acknowledging the common understanding in regard to salvation for Palestinian Jews from the time of Jesus.

The four Gospels are concerned with this time of Jesus +/- “law” (for example, laws on purity and eating, as explored by Dunn) which Paul was alluding to.