The Catholic Study Bible treats I Maccabees as a foil for the New Testament, especially in its treatment of the Gentiles. It states:
"I Maccabees has importance also for the New Testament. Salvation is paralleled with Jewish national aspirations (1 Mc 4, 46-14, 41), in contrast to the universal reign of God taught by Christ in the Gospel (Mt 13, 47-50; 22, 1-14). Also, destruction of the wall of the temple separating Jew and Gentile is an act of desecration in 1 Mc 9, 54, but in Eph 2, 14, an act of redemption and unification of both through Christ" (550).
And that's the impression I get from I Maccabees: the Gentiles are double-crossers. The author is slightly disposed to the Romans, for he says in I Maccabees 8 that their leaders did not display any pomposity, and that there was no jealousy or envy within their Senate ("Yeah, right!," say many historians). But, overall, the Maccabees do not care a great deal for the Gentiles. In I Maccabees, Israel is basically fighting for its own national traditions--for the laws that God gave to Israel when he set her apart.
In contrast, the early Christians actually cared about their Gentile oppressors. When they were dragged before governors and kings, the Holy Spirit enabled them to testify to the nations (Matthew 10:18-20). In I Timothy 2:1-4, Paul (or, for liberal scholars, "Paul") tells Timothy to pray for kings, since God desires for all to be saved and to come to a knowledge of the truth. It's not "Look at me! I'm dying for these customs that God gave to my nation. May God destroy you, you filthy heathens!" Rather, the Christian martyrs hoped that their persecutors would come to know Christ as Lord. And, as the old saying goes, "The blood of the martyrs became the seed of the church."
By contrast, the Catholic Study Bible says that II Maccabees is more positive about the Gentiles:
"...as opposed to the Greeks as 2 Maccabees is, it is not simplistic in the way it deals with Jews and Greeks. It presents some Greeks as sympathetic to the Jews. Antiochus even converts on his deathbed (9, 11-18). Clearly the Jews do not object to the rule of the Gentiles as such. The Jews can be good citizens. What they do object to are the abuses that came with Antiochus" (RG 228).
And that is true. In II Maccabees 3, when God struck down the Seleucid Heliodorus for trying to rob the temple, the righteous priest Onias III offered an atonement sacrifice for the man's recovery (partly so the Seleucids wouldn't think there was foul play). Heliodorus then worshipped God and bid Onias farewell.
Antiochus Epiphanes gets angry when Onias III is murdered, so he executes the killer (II Maccabees 4:38).
When the Seleucid general Nicanor is about to slaughter Jews on the Sabbath, some Jews ask him to honor God's holy day (II Maccabees 15:1-5). Maybe this passage means that Gentiles should observe the Sabbath. Or maybe it's just saying that Nicanor should revere the day that God gave to the Jews, since God is supreme, and anything associated with him deserves respect. Either way, Nicanor is expected to honor the God of the Jews. That differs from what seems to be I Maccabees' message, which is that God is on the side of the Jews, and (presumably) no one else.
And Nicanor eventually becomes friends with Judah the Maccabee, even though he's constrained by the Seleucids to turn against him in the end (II Maccabees 15:17ff.).
II Maccabees treats the Gentiles much like the New Testament does: they have the potential for virtue and piety. Similarly, Jesus in Luke's Gospel appealed to the Old Testament example of Naaman as a righteous Gentile (Luke 4:27), and he praised the Gentiles who demonstrated more faith than did many Israelites (Luke 7:9).