Paul, as a pattern and example of those who live as an accurate representation of God, the Father and Christ the son on the earth, exhorts the Philippian church to press on to lay hold of that which Christ laid hold of him for (i.e. Maturity - Teleios).
The church of God must not just be satisfied with the forgiveness of sins, and the opening of a new way to access God that was as a result of the cross, but we must endeavour to become the full expression of all that God had in mind when he rescued us with the precious and priceless blood of Jesus.