Loss is gain.

In chapter 3, Paul gives his credentials as the Jew who punished Christians: Circumcised on the 8^th day; a member of the people of Israel; of the tribe of Benjamin; Hebrew born of Hebrews; as to the law a Pharisee; as to zeal, a persecutor of the church; as to righteousness under the law, blameless (verse 6).

By becoming a Christian he had lost all of that Pharisaical prestige in gaining Christ. A good explanation of “loss is gain” follows in verses 7 to 14. 

The athletic imagery is back in verses 13 and 14. All Christians are striving for the prize of “the high calling of God in Christ Jesus.”

Paul claims perfection for himself and his listeners/readers, but knows that God will reveal what needs correcting on the human plane, and will direct that correction.

The NRSV speaks of “rival missionaries.” There are those who opposed the Philippians in their striving to be Christians doing Christ's work; just as they opposed Paul.

Joyce Voysey

Ed. The phrase "loss is gain" appears in hymns 174 and 207, the latter from the poem "Mother's Evening Prayer" by Mary Baker Eddy. Eddy uses the phrase again in her Miscellaneous Writings p. 111: 9-13, p. 116: 15-19, p. 358: 6- 8.