"All souls are mine, saith the Lord, and the soul that sinneth, it shall die."
James wrote there is only one Lawgiver. Since sin is a transgression of the law, the Lawgiver, as Righteous Judge, will determine and interpret His Law according to the good pleasure of His will, and so, will decide who among the vast crowds of humanity that never heard of Jesus from A.D. 33 forward, has actually transgressed His Law, or not.
For me, this is where
Revelation 20 comes into play. The books will be opened, and the dead will be judged by them. A lot of people think this refers to the 66 books of the Bible, but that is mere interpretation not actually verified by the passage, i.e. it is an assumption.
In any case, the truth is, is that this judgement is mere frivolity if the outcome has already been settled. The key phrase is "And whosoever was not found written in the book of life was cast into the lake of fire" (v. 15). After all the dead were given up, and the books were opened, and the Book of Life was opened, and each received a judgment from the Lord, according to their works (v. 12), any whose name isn't found in the Book of Life is destroyed in the lake which burns...
This, to me at least, strongly suggests the possibility that there were will be some of these dead, whose name is going to be found in the Book of Life, after they are judged according to their works.
I can only imagine these are those who never had a chance to believe on Him whom the Father has sent.