Indeed We do send down this Qur’an (Reading) upon you stage by stage.
By saying ‘this Qur’an’ in the verse we can understand that Scriptures sent down before Muhammad were ‘Qur’an’ i.e., Vedas, Zaboor, Thorah, Injeel etc. Totally 313 Qur’ans were sent down with 313 Messengers to the Earth by Allah. So all the Books have same soul, but their bodies differ as they are in different languages. The verses have been revealed stage by stage in order to make It crisp and clear to Prophet’s mind is mentioned in the verse 25: 32.
Today Adhikr is the ultimate form of previous Scriptures, which testifies and safeguards all previous Books. Scriptures have been revised periodically without having any changes in the basic principles. And these versions have been made not to differentiate among mankind as Hindus, Christians, Jews, Muslims etc., but to unite them as a single community. See the explanation 5: 48; 21: 24 and 41:43 in the Splendid Book from the Three Times Knower.