Paul say that “I have learned to be content in whatever circumstances I am” (Philippians 4:11). That’s not to say that Paul had found a state of being that was free from suffering, disasters, or opposition. Rather, he was able to embrace all hardships as essential components of God’s sovereign plan. The contentment (autarkēs in the Greek) he describes transcends all of those things. His union with Christ brought with it a profound sense of satisfaction and independence from worldly distractions. And that was because Paul’s dependence and sufficiency were found in Christ: “I can do all things through Him who strengthens me” (Philippians 4:13).
John MacArthur elaborates further:
Paul was saying, “I have learned to be sufficient in myself—yet not in myself as myself, but as indwelt by Christ.” He elsewhere expressed that subtle distinction: “I have been crucified with Christ; and it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me, and delivered Himself up for me” (Galatians 2:20). Christ and contentment go together.
But I rejoiced in the Lord greatly, that now at last you have revived your concern for me; indeed, you were concerned before, but you lacked opportunity. Not that I speak from want, for I have learned to be content in whatever circumstances I am. I know how to get along with humble means, and I also know how to live in prosperity; in any and every circumstance I have learned the secret of being filled and going hungry, both of having abundance and suffering need. I can do all things through Him who strengthens me. Nevertheless, you have done well to share with me in my affliction.