How is Judaism and Christianity and Islam worship connected to their beliefs?

Answer 1

Maybe because they all appear to have originated from the same book?

According to islamic sources, the Qur'an was introduced to 'Muhammad' by the parental cousin( 'Waraka ibn Nawfal' ), of his first wife 'Kadijah'.

Waraka was a Christian Ebionite Priest living in Mecca, and one who had made detailed studies of the Gospels and the Old Testament scriptures.

Muslim tradition maintains that Waraka was one of the believers in the Age of Ignorance, meaning that he was a believer before the prophecy of Muhammad. Waraka would frequently contemplate and pray at the Kaaba and began to read the Biblical texts in their original language and even learned to read Hebrew. Around this time, Waraka, with another member of his tribe, is said to have found Muhammad as a young infant and immediately returned him to Abdul Muttalib, which has been interpreted to be a foreshadowing to his acceptance of Muhammad's prophecy.

As Muhammad grew in age, Waraka's knowledge of the sacred scriptures increased. Several years later, when told of Muhammad's first revelation (which is understood to be Q. XCVI: 1-5), Waraka recognized his call to prophecy as authentic and tradition recounts Waraka saying: "There has come to him the greatest Law that came to Moses; surely he is the prophet of this people".

Waraka, upon accepting Muhammad's prophecy, remained a Christian and, in later accounts, was counted among Muhammad's companions.

Muhammad is later said to have said of Waraka: "Do not slander Waraka ibn Nawfal, for I have seen that he will have one or two gardens in Paradise."

Sources:

Encyclopedia of Islam, Online ed., Waraka b. Nawfal

Ibn Hisham, The Life of Muhammad, 3rd ed., vol. 1, pt. 2, p. 73.

Reading Islam.com What Really Happened Up There?

Saheeh al-Jaami as-Sagheer, 6/1534, no. 7197