At the time of writing this letter Paul was in prison, one of his experiences of "suffering" for Christ. He knew from the early days of his Christian life that he would be persecuted for the cause of Christ. He didn't shy away from that but recognized what he would say in II Timothy, "All those who live godly in Christ Jesus will suffer persecution." And he was willing to do so because it meant that he was fighting for souls in the "enemies' territory." Satan will do all he can to hinder the preaching of the Gospel to the lost. And he will seek to kill or at least imprison those who seek to do so. Paul knew it was because he preached to the Gentiles that he was especially hated by the Jewish authorities who thought the Gentiles were too vile to be saved. So even if it meant imprisonment, Paul would do all he could to give these "vile sinners" the opportunity to hear about Christ and be gloriously saved and transformed. That's why he knew he was in prison "for the benefit of your Gentiles." What would you be willing to endure so others could hear about our Savior?