Not eternal salvation from God's condemnation and from the lake of fire but the daily salvation that is a living Person. This daily salvation results from taking the very Christ whom we live, experience, and enjoy as our inward as well as outward pattern. The main elements of this salvation are Christ as the crucified life (vv. 5-8) and Christ in His exaltation (vv. 9-11). When this pattern becomes the believers' inward life, the pattern becomes their salvation. Only this would make the apostle's joy full.
In ch. 1 salvation comes through the bountiful supply of the Spirit of Jesus Christ, but here salvation comes from the operating God within us. The operating God is actually the Spirit of Jesus Christ. In both these cases salvation is a practical, daily, moment-by-moment salvation. The constant salvation in Phil. 1:19 is one in which a particular believer is saved from a specific encounter in a particular situation; whereas the constant salvation in Phil. 2:12 is one in which any believer is saved from ordinary things in common situations in his daily living.