Romans 11:6

But if it is in His grace that He has selected them, then His choice is no longer determined by human actions. Otherwise grace would be grace no longer.

Romans 3:27-28

Where then is there room for your boasting? It is for ever shut out. On what principle? On the ground of merit? No, but on the ground of faith.

Romans 4:4-5

But in the case of a man who works, pay is not reckoned a favour but a debt;

Romans 5:20-21

Now Law was brought in later on, so that transgression might increase. But where sin increased, grace has overflowed;

1 Corinthians 15:10

But what I am I am by the grace of God, and His grace bestowed upon me did not prove ineffectual. But I labored more strenuously than all the rest--yet it was not I, but God's grace working with me.

Galatians 2:21

I do not nullify the grace of God; for if acquittal from guilt is obtainable through the Law, then Christ has died in vain."

Galatians 5:4

Christ has become nothing to any of you who are seeking acceptance with God through the Law: you have fallen away from grace.

Ephesians 2:4-9

But God, being rich in mercy, because of the intense love which He bestowed on us,

2 Timothy 1:9

For He saved us and called us with a holy call, not in accordance with our desserts, but in accordance with His own purpose and the free grace which He bestowed on us in Christ Jesus before the commencement of the Ages,

Titus 3:5

as righteous men, had done, but as the result of His own mercy He saved us by means of the bath of regeneration and the renewal of our natures by 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 there room for your boasting? It is for ever shut out. On what principle? On the ground of merit? No, but on the ground of faith.
Romans 4:4
But in the case of a man who works, pay is not reckoned a favour but a debt;
Romans 5:20
Now Law was brought in later on, so that transgression might increase. But where sin increased, grace has overflowed;
1 Corinthians 15:10
But what I am I am by the grace of God, and His grace bestowed upon me did not prove ineffectual. But I labored more strenuously than all the rest--yet it was not I, but God's grace working with me.
Galatians 2:21
I do not nullify the grace of God; for if acquittal from guilt is obtainable through the Law, then Christ has died in vain."
Galatians 5:4
Christ has become nothing to any of you who are seeking acceptance with God through the Law: you have fallen away from grace.
Ephesians 2:4
But God, being rich in mercy, because of the intense love which He bestowed on us,
2 Timothy 1:9
For He saved us and called us with a holy call, not in accordance with our desserts, but in accordance with His own purpose and the free grace which He bestowed on us in Christ Jesus before the commencement of the Ages,
Titus 3:5
as righteous men, had done, but as the result of His own mercy He saved us by means of the bath of regeneration and the renewal of our natures by the Holy Spirit,

General references

Acts 28:24
Some were convinced; others refused to believe.
Romans 4:4
But in the case of a man who works, pay is not reckoned a favour but a debt;
Ephesians 2:9
so that it may be impossible for any one to boast.