Has there ever been a just man?

Bible vs Quran

Yes

Nephi, Jacob, and Joseph, Sam, and Shiblon were just and holy men.

Nephi, Jacob, and Joseph, and Sam ... were just and holy men. Alma 3:6

Shiblon ... was a just man, and he did ... keep the commandments Alma 63:1-2

And so was the other Nephi (the son of Helaman Jr.)

We know our record to be true, for behold, it was a just man who did keep the record. 3 Nephi 8:1

No

For there is not a just man upon earth, that doeth good, and sinneth not. Ecclesiastes 7:20