The Quran says:
“Surely those who believe, and those who are Jews, and the Christians, and the Sabians — whoever believes in God and the Last Day and does good, they shall have their reward from their Lord. And there will be no fear for them, nor shall they grieve.” (The Holy Quran 2:62 )
“…and nearest among them in love to the believers will you find those who say, ‘We are Christians,’ because amongst these are men devoted to learning and men who have renounced the world, and they are not arrogant” (The Holy Quran 5:82)
“Indeed, Allah is with those who are righteous and those who do good”. (Al Quran 16:129)
“The reward of goodness is nothing but goodness”. (Al Quran 55:61)
This is what the Islamic teaching say about "people of the book" that will say, Christians, Jews, and Muslims