5 Even so then, at this present time there is a remnant according to the election of grace.
6 And if by grace, then it is no longer of works; otherwise grace is no longer grace. But if it is of works, it is no longer grace; otherwise work is no longer work.
There were still some Jews saved by grace. Paul offers this as further evidence that God hasn’t forsaken the nation of Israel.
Grace is not grace if mixed with works. The two principles are mutually exclusive (Romans 4:4-5). Thus in salvation there is no “your part” to perform; it is the gift of God’s love, to be received in simple faith (Romans 6:23; Ephesians 2:8-9) — Stam, page 266