Romans 11:6

And if it is by grace, it is no longer on account of works; otherwise grace ceaseth to be grace; but if it is of works, there is then no grace; otherwise work ceaseth to be work. How is it then?

Romans 3:27-28

Where then is the boasting? It is excluded. By what law? of works? Nay; but by the law of faith.

Romans 4:4-5

Now to him that performeth works, the reward is not accounted a matter of grace, but of debt;

Romans 5:20-21

Moreover the law came in in addition, that the trespass might abound; but where sin abounded, grace abounded much more;

1 Corinthians 15:10

But by the grace of God I am what I am; and his grace which was bestowed upon me was not in vain, but I labored more abundantly than they all; yet not I, but the grace of God which was with me.

Galatians 2:21

I do not set aside the grace of God; for if righteousness come through the Law, then did Christ die for nought.

Galatians 5:4

Ye are entirely separated from Christ, who seek to obtain righteousness through the Law; ye have fallen away from grace.

Ephesians 2:4-9

but God, who is rich in mercy, on account of his great love wherewith he loved us, gave to us,

2 Timothy 1:9

who saved us, and called us with a holy calling, not according to our works, but according to his own purpose and the grace which was given us in Christ Jesus before the world began,

Titus 3:5

not by works of righteousness which we did, but according to his mercy he saved us, by the bath of regeneration, and renewing of the Holy Spirit,

Treasury of Scripture Knowledge

Summary

And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work.

General references

Bible References

And if

Romans 3:27
Where then is the boasting? It is excluded. By what law? of works? Nay; but by the law of faith.
Romans 4:4
Now to him that performeth works, the reward is not accounted a matter of grace, but of debt;
Romans 5:20
Moreover the law came in in addition, that the trespass might abound; but where sin abounded, grace abounded much more;
1 Corinthians 15:10
But by the grace of God I am what I am; and his grace which was bestowed upon me was not in vain, but I labored more abundantly than they all; yet not I, but the grace of God which was with me.
Galatians 2:21
I do not set aside the grace of God; for if righteousness come through the Law, then did Christ die for nought.
Galatians 5:4
Ye are entirely separated from Christ, who seek to obtain righteousness through the Law; ye have fallen away from grace.
Ephesians 2:4
but God, who is rich in mercy, on account of his great love wherewith he loved us, gave to us,
2 Timothy 1:9
who saved us, and called us with a holy calling, not according to our works, but according to his own purpose and the grace which was given us in Christ Jesus before the world began,
Titus 3:5
not by works of righteousness which we did, but according to his mercy he saved us, by the bath of regeneration, and renewing of the Holy Spirit,

General references

Acts 28:24
And some believed the things spoken, and some believed not.
Romans 4:4
Now to him that performeth works, the reward is not accounted a matter of grace, but of debt;
Ephesians 2:9
not of works, lest any one should boast.