قَالَ: أَنْ تُؤْمِنَ بِاللَّهِ وَمَلَائِكَتِهِ وَكُتُبِهِ وَرُسُلِهِ وَالْيَوْمِ الْآخِرِ، وَتُؤْمِنَ بِالْقَدَرِ خَيْرِهِ وَشَرِّهِ. قَالَ: صَدَقْتَ، قَالَ: فَأَخْبِرْنِي عَنِ الْإِحْسَانِ
Translation: He replied: Iman is to believe in Allah, His angels, His books, His messengers, the Last Day, and divine decree in its good and bad aspects. The visitor confirmed the answer and asked about Ihsan.
The answer about Iman lists belief in Allah, His angels, His revealed books, His messengers, the Last Day, and divine decree—its good and its bad. These are matters of belief accepted on the basis of Allah's and His Messenger's guidance.
In تُؤْمِنَ بِاللَّهِ, the verb for believing is followed by بِـ. The suffix ـهِ in مَلَائِكَتِهِ، كُتُبِهِ، رُسُلِهِ refers to Allah: His angels, His books, and His messengers.
The list organizes core beliefs for a beginner. Detailed exposition of each belongs to later study.