Accordingly, we testify that whoever believed in Moses and followed him was a believer, a Muslim, and therefore entitled to reward.
Likewise, whoever believed in the Messiah and followed him falls under the same judgment.
And we bear witness that those upon whom the proof established by Moses was conveyed but who still refused to follow him—such as Pharaoh’s people—are among the inhabitants of the Fire.
The same applies to those upon whom the proof established through the Messiah was conveyed, of whom Allah said:

“Allah said, ‘Indeed, I will send it down to you; but whoever among you disbelieves thereafter, I shall punish him with a punishment such as I have never inflicted upon anyone in all the worlds.’” (al-Ma’idah 5:115)

and of whom He also said:

“[Remember] when Allah said, ‘O Jesus, I will cause you to die, raise you to Myself, purify you from those who disbelieve, and place those who follow you above those who disbelieve until the Day of Resurrection. Then to Me you will all return, and I will judge between you regarding whatever you used to dispute. As for those who disbelieved, I shall punish them with a severe punishment in this world and the Hereafter, and they will have no helpers. But those who believed and did righteous deeds, He will grant them their full rewards; and Allah does not love the wrongdoers.’” (Al-‘Imran 3:55–57)

As for the people who lived long after the time of the Messiah—and only some reports about him reached them—or those who lived long after Moses and likewise received only part of the reports about him, the proof is established against them in proportion to whatever of those reports did reach them, not with respect to what failed to reach them.
And when they disagree over the interpretation of portions of the Torah or the Gospel, then whoever genuinely seeks the truth and strives for it is not obliged