Ephesians 2:8-9
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.
Romans 3:23
... for all have sinned and fall short of the glory of God ...
1 Corinthians 1:30-31
... by His doing you are in Christ Jesus, who became to us wisdom from God, and righteousness, and sanctification, and redemption that, just as it is written, “Let him who boasts, boast in the Lord.”