James 2:10

For whoever obeys the whole law, except to slip in a single instance, is guilty of breaking it all.

Galatians 3:10

For those who depend on what the law commands are under a curse, for the Scripture says, "Cursed be everyone who does not continue in all the commands that are written in the book of the law, to do them."

Matthew 5:18-19

I have not come to set them aside but to fill them up to the brim. For I solemnly say to you, heaven and earth would sooner pass away than the dotting of an 'i' or the crossing of a 't' from the law, until it all becomes in force.

Treasury of Scripture Knowledge

Summary

For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all.

Bible References

Whosoever

Matthew 5:18
I have not come to set them aside but to fill them up to the brim. For I solemnly say to you, heaven and earth would sooner pass away than the dotting of an 'i' or the crossing of a 't' from the law, until it all becomes in force.
Galatians 3:10
For those who depend on what the law commands are under a curse, for the Scripture says, "Cursed be everyone who does not continue in all the commands that are written in the book of the law, to do them."