Faith in Allah’s books is believing wholeheartedly that Allah SWT. has revealed the holy books to His apostles as guidance and guidance for life for mankind. The Koran is also called Kalmullah (God’s Word). Allah also speaks, not like ordinary creatures, but Allah speaks with His majesty and power. A Muslim also believes that all these books really come from Allah, although only the Koran is still preserved in its authenticity and is a guide for all mankind until the end of time.