For it is by grace you have been saved, through faith—and this is not from yourselves, it is the gift of God– not by works, so that no one can boast.
It is God’s grace alone that saves us. Earlier in this passage, we are told that it is His great love for us, even when we were dead in sin, that He made us alive in Christ. It is His gift to us. We can’t earn it, we just have to receive this grace BY FAITH. In this passage, Paul also recognizes man’s natural tendency to brag about our performance and he shut it down.
God’s abundant grace and gift of salvation are free to all who have faith in Christ and receive it! Ephesians 2:10 then says ““For we are God’s handiwork, created in Christ Jesus to do good works, which God prepared in advance for us to do.” God then empowers us to do the work which in turn glorifies Him.