As it is known that in Islam there are six pillars of faith. The third pillar is to believe in the books of God. Therefore, Muslims are obliged to believe and trust it.
God says in the Quran surah Ali Imran verse 3:
نَزَّلَ عَلَيْكَ الْكِتَابَ بِالْحَقِّ مُصَدِّقًا لِمَا بَيْنَ يَدَيْهِ وَأَنْزَلَ التَّوْرَاةَ وَالْإِنْجِيلَ
The verse explains that as Muslims must believe the book before the Quran, because they are true and are revealed to the messenger.
The books before the Quran are the Torah, Zabur, and the Gospel. But now the Holy Quran is the source of guidance of Muslims.
Believe in the books before the Quran
1. Believing that the Torah, Zabur, and gospels are really revelations revealed by Allah Subhanahu wa ta’ala, not the essays or made by the apostles. The Apostle is a human being sent by God almighty to spread the teachings of Islam and the recipient of revelation.
2. Believing that the contents of these books are true.
How to believe in the Quran as Book of God
1. Believing that the Quran is a revelation revealed by Allah Subhanahu wa ta’ala and delivered by the Prophet Muhammad Shallallahu alaihi wassallam and is not a mere essay.
2. Learn the contents of the Quran. Through this step it will increase one’s faith.
3. Practice the teachings of the Quran in everyday life. This is proof that the Qur’an is a guide to life for Muslims.
4. Reading the Quran, in addition to believing that the Qur’an is a revelation of Allah Subhanahu wa ta’ala delivered through the Prophet Muhammad Shallallahu alaihi wassallam, Muslims should read the Qur’an properly and correctly is one way to believe in the book of God.