Romans 10:4

For Christ is the end of the law unto righteousness to every one that believeth.

End of the law ... does not refer to the abrogation of Moses' law (though, of course, it was abrogated by Christ, as amply taught elsewhere), but to the goal, end, and fulfillment of the law's purpose As Whiteside pointed out:

It is true that the law ended at the cross, but it ended at the cross regardless of whether one believes or disbelieves. The end of which Paul here speaks is attained by those who believe in Christ. The end, or aim, of the law was righteousness. The believer in Christ is made righteous, and thus the end of the law for righteousness is reached in Christ. When a man's sins are all blotted out, when he is cleansed from sin, he is righteous; that condition is reached in Christ by those who believe .... The modifying clause, "to every one that believeth," shows that Paul was not speaking of the abrogation of the law; that is taught abundantly elsewhere. And it was abrogated for all, believers and unbelievers alike.[4]

For righteousness ... The end, or aim, of the law was to produce righteousness; but the only person who ever lived to achieve perfect fulfillment of the law, thus achieving that righteousness, is the Lord Jesus Christ. All who are "in Christ" therefore have fulfilled the law "in him"; that is, when viewed as Christ, they have fulfilled it.