"For it is by grace you have been saved, through faith—and this not from yourselves, it is the gift of God—not by works, so that no one can boast" (Ephesians 2:8-9). Don't stop there. Read the next verse. "For we are God’s workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do" (v. 10).
In salvation, God is the poet and we are His poetry in motion. We are saved by His grace and through faith alone. Not by our works but for good works.
Understanding this important theological distinction is the difference between maintaining the purity of the gospel and distorting it.