Allah will judge between the Sects on the Day of Resurrection 

Allah says:

إِنَّ الَّذِينَ امَنُوا وَالَّذِينَ هَادُوا وَالصَّابِيِينَ وَالنَّصَارَى وَالْمَجُوسَ وَالَّذِينَ أَشْرَكُوا إِنَّ اللَّهَ يَفْصِلُ بَيْنَهُمْ يَوْمَ الْقِيَامَةِ
 
إِنَّ اللَّهَ عَلَى كُلِّ شَيْءٍ شَهِيدٌ
 
 

Verily, those who believe, and those who are Jews, and the Sabians, and the Christians, and the Majus, and those who worship others besides Allah; truly, Allah will judge between them on the Day of Resurrection.

Verily, Allah is over all things a Witness.

Allah tells us about the followers of these various religions, the believers (Muslims) and others such as the Jews and Sabians.

We have already seen a definition of them in Surah Al-Baqarah and have noted how people differ over who they are. There are also the Christians, Majus and others who worship others alongside Allah. Allah will (
يَفْصِلُ بَيْنَهُمْ يَوْمَ الْقِيَامَةِ
 judge between them on the Day of Resurrection) with justice;

He will admit those who believed in Him to Paradise and will send those who disbelieved in Him to Hell, for He is a Witness over their deeds, and He knows all that they say and all that they do in secret, and conceal in their breast