One of Allah’s abundant mercies to mankind is that He sent Prophets and Messengers (peace be upon them all) from among people themselves. These Prophets were held the highest status among mankind in terms of character and moral integrity.
Allah (glory be to Him) sent down revelation to them, that would serve to clearly establish mankind’s relationship with their Creator and provide a divine methodology by which they could purify their hearts and live as believers. These books also help establishing a law in which the prevalence of justice and morality strengthen the community’s bonds.
If people believe in these Books and live according to the divine law contained in them, they will live happily and eventually attain peace in this world and the Hereafter.
It is obligatory on all Muslims to believe in all books revealed by Allah to His Messengers (peace be upon them all). Anyone who doubts or disbelieves in these books is not considered a Muslim because they are disbelieving the Qur’an which mentions them.
Almighty Allah says:
“O you who believe! Believe in Allah, in his Messenger, and the Book which He has sent down to His Messenger, and the Scripture which He sent down to those before him; and whosoever disbelieves in Allah, His Angels, His Books, His Messengers, and the Last Day, then indeed he has strayed far away. (An-Nisaa’ 4:136)
The Glorious Qur’an specifically referred to the divine Books, namely Abraham’s Scriptures, David’s Psalms, Moses’ Torah, and Jesus’ Gospel. The following verses illustrate this point. Allah (exalted be He) says in the Quran:
Allah! There is no divinity other than Him; the Ever Living, the One Who sustains and protects all that exists. It is He Who has sent down the Book (the Quran) to you with truth, confirming what came before it. And He sent down the Torah and Gospel. (Aal `Imran 3:2-3)
And to David We gave the Psalms. (An-Nisaa’ 4:163)
Verily, this is in the former Scriptures. The Scriptures of Abraham and Moses. (Al-A`la 87:18-19)
The Glorious Qur’an is the miraculous word of Allah revealed to the Prophet Muhammad (peace be upon him) in the Arabic language via Gabriel, the Angel of revelation also known as the Holy Spirit (16:102).Source Link