[3:75] And of the People of the Scriptures is he who, if you trust him with a hundredweight, he will return it to you; and of them is he who, if you trust him with one dinar, will not return it to you…
He informs us that they, in spite of their error and disbelief, are different in their moral qualities. All of them are unfaithful to the religion (dīn), but among them are those who return to proper (human) interactions. Even though they interact with sincerity, it will not benefit them in the granting of the reward, but it will benefit them in lessening the punishment since disbelievers are held accountable in the details of the laws. If, in their disbelief they sinned less, they will suffer less punishment than those who have lost the most, even though their punishment will also be eternal.
Then He explained that the judgment is not theirs, so that when they say, 'We have no duty towards the Gentiles' [3:75] this situation is not as they believe, nor do these words benefit them. Rather, the judgment belongs to God (s).