One must believe in all the books that has been sent down from the Most High God. What do we mean by books sent down? How can we tell if a book has been sent? The guidance of understanding and knowledge come by way of spirit that comes from the Most High. Books are revealed by way of an Angel coming down to a human being. The Angel tells the human what thus saith the Lord or what the Lord has said. These are words from on high. There is an unseen world and if the angel shows the person something or conversations of the unseen world that is called revelation. Not just anything in the unseen world but things of the highest heavenly realm. The Books of the Most High God origins are from a heavenly place. The receiver of the books are called Prophets of the Lord Most High. After the Prophet then comes a messenger to confirm the book.
Q2:285 The Messenger has believed in what was revealed to him from his Lord, and [so have] the believers. All of them have believed in Allah and His angels and His books and His messengers, [saying], “We make no distinction between any of His messengers.” And they say, “We hear, and we obey. [We seek] Your forgiveness, our Lord, and to You is the [final] destination.”
A person cannot be a believer unless they believe in every single book that came down from The God. I will provide you with the books the Islamic House of Islam believes in. We believe in psalms, Quran, Torah, the books of the prophets (Jeremiah, Daniel, Malachi etc.), Book of Revelations, Enoch 1, Book of Jubilee, and all the Hebrew Bible which is the so-called Old Testament. There are many prophecies in these books that have not been fulfilled yet, so these books are always relevant. Especially to an Israelite in this day and time. Splitting these books up is forbidden they all form a puzzle. One book is needed with the other. Are you a Prophet? No, I teach from the books the prophets I was sent to clarify, and to give the correct interpretation of them. I am a messenger of God not a prophet. Prophets are messengers but not all messengers are prophets.
Q4:136 O you who have believed, believe in Allah and His Messenger and the Book that He sent down upon His Messenger and the Scripture which He sent down before. And whoever disbelieves in Allah, His angels, His books, His messengers, and the Last Day has certainly gone far astray.
Disbelief in his books surely will cause a person to go astray. The puzzle will be incomplete. The Quran establishes the 4 sacred months it mentions one month by name Ramadan, but the Torah mentions the other 3 sacred months. But to find out the month count you need the book of Enoch for the calendar. The book of Jubilee gives us clarification of the year count and what happens within the months. Can you see how all the books work together to get us on the right track? I am here to make this known. There are books we do not believe in because God himself nor an angel brought it down. We should never put these books against each other, nor should we create sects from these books. If you do not believe in these books, then you are not a part of the believing congregation.