Salam brothers and sisters
5:69
Indeed, those who believed and those who became Jews and the Sabians and the Christians, whoever believed in Allah and the Last Day and did good deeds, then no fear on them and not they will grieve.
2:62
Indeed, those who believed and those who became Jews and the Christians and the Sabians - who believed in Allah and the Day [the] Last and did righteous deeds, so for them (is) their with their Lord and no fear on them and not they will grieve.
I have thought about these verses, the Quran clearly mentions them with groups of people whose faith is described as those who believed in Allah, in the Last day and did good deeds. So, they were a group of people who believed these and did good deeds, just like us. I guess that should be enough, since other statements about them cannot be made from the Quran.