After instructing the Philippians to live in such a way that they might experience the joy of the Lord and the peace of God, Paul sums up his admonition by telling them to practice what they have learned and received and heard and seen in him. They had been discipled and taken the instruction to heart. They had also witnessed what the Christian life looks like by watching and listening to Paul while he lived among them. Paul was encouraging them to follow him as he followed Christ for biblical doctrine is intended to change the way we live.