Short answer
No, not in itself. Learning about other religions to understand your neighbours, to explain Islam, or for school and university is allowed, and a Companion learned the writing of the Jews at the Prophet's ﷺ instruction. Scholars advise anyone whose own faith is not yet firm to learn Islam well first and to study other beliefs with a knowledgeable guide.
Learning about other religions for a valid purpose, such as da'wah, scholarship, education or dialogue, is permissible, and having some experts in it serves the community. Taking guidance in worship from other scriptures is not permitted, and neither is study that plants doubts in someone not yet grounded in Islam.
The four schools agree on this.
Explanation
Zayd ibn Thabit said the Prophet ﷺ told him to learn the writing of the Jews so that he could read and write letters for him, and he learned it in a short time. The Prophet ﷺ also allowed Muslims to narrate from the Children of Israel, and taught a balanced rule for what they report from their books: do not believe them and do not deny them. The Quran says people were made into nations "that you may know one another".
Muslim scholars have a long record here. Al-Shahrastani wrote a famous survey of the world's religions and sects, al-Biruni studied Indian religion in depth, and the Hanafi scholar Rahmatullah Kairanawi studied the Bible closely to answer missionaries in Izhar al-Haqq.
- School RE or university courses: fine. Learn the material, and keep learning your own faith alongside it.
- Reading the Bible: see can Muslims read the Bible?
- Visiting places of worship for study: see can Muslims go to church?
- Online debates: if they leave you confused rather than informed, step back and bring your questions to a scholar.
The purpose shapes the ruling. Studying to understand and to invite "with wisdom and good instruction" is good. Taking practices of worship from other faiths, or reading to feed doubts with no one to guide you, is not. A young Muslim with questions should talk to a teacher they trust rather than face them alone.
The evidence
Quran, Surah Al-Hujuraat 49:13
يَٰٓأَيُّهَا ٱلنَّاسُ إِنَّا خَلَقْنَٰكُم مِّن ذَكَرٍۢ وَأُنثَىٰ وَجَعَلْنَٰكُمْ شُعُوبًۭا وَقَبَآئِلَ لِتَعَارَفُوٓا۟ ۚ إِنَّ أَكْرَمَكُمْ عِندَ ٱللَّهِ أَتْقَىٰكُمْ ۚ إِنَّ ٱللَّهَ عَلِيمٌ خَبِيرٌۭ ﴿١٣﴾
O mankind, indeed We have created you from male and female and made you peoples and tribes that you may know one another. Indeed, the most noble of you in the sight of Allah is the most righteous of you. Indeed, Allah is Knowing and Acquainted.
Knowing other peoples, including their beliefs, has a place in Islam.
Quran, Surah An-Nahl 16:125
ٱدْعُ إِلَىٰ سَبِيلِ رَبِّكَ بِٱلْحِكْمَةِ وَٱلْمَوْعِظَةِ ٱلْحَسَنَةِ ۖ وَجَٰدِلْهُم بِٱلَّتِى هِىَ أَحْسَنُ ۚ إِنَّ رَبَّكَ هُوَ أَعْلَمُ بِمَن ضَلَّ عَن سَبِيلِهِۦ ۖ وَهُوَ أَعْلَمُ بِٱلْمُهْتَدِينَ ﴿١٢٥﴾
Invite to the way of your Lord with wisdom and good instruction, and argue with them in a way that is best. Indeed, your Lord is most knowing of who has strayed from His way, and He is most knowing of who is [rightly] guided.
Knowledge of others helps Muslims explain Islam well.
Jami' at-Tirmidhi 2715
Grading to be checked... أمرني رسول الله صلى الله عليه وسلم أن أتعلم له كلمات من كتاب يهود ...
"Zayd ibn Thabit said: the Messenger of Allah told me to learn the writing of the Jews for him."
Learning about another community's scripture and language for a purpose is allowed.
Sahih al-Bukhari 4485
Sahih... لا تصدقوا أهل الكتاب ولا تكذبوهم ...
"Do not believe the People of the Book and do not deny them."
A balanced approach to what other scriptures contain.
Where the ruling is recorded
- Izhar al-Haqq (Rahmatullah Kairanawi), the introduction. An example of a Hanafi scholar studying another religion's scripture in depth for da'wah.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.