I believe that the christian and jews who were not aware of that but they were sincere in obeying God such that if they knew the truth would follow it are all going to Heaven.

Verily! Those who believe and those who are Jews and Christians, and Sabians, whoever believes in Allâh and the Last Day and do righteous good deeds shall have their reward with their Lord, on them shall be no fear, nor shall they grieve. (62)

God knows the heart of the people and He understand the motivation behind their behavior. No one will be lost if he was truely seeking the Truth.