Quran is not contesting for the title of the "Loving" book, rather it is the word of Almighty. It is the belief of muslims that there is not a single word there which is untrue.
Christians were a blessed nation, just as jews were. However if a nation deviates from the right path (the path which the Almighty revealed to the people through His messangers, Moses, Christ and Muhammad (peace and blessings be upon them all), then it deserves the wrath of Almighty. Muslims are no exception.
The verses which you have taken from the Quran are addressed to the christians who have deviated from the message of God.
Quran explains the birth of Christ and says that Christ is not the son of God, as God has no son nor a father. Similarly Quran present the true narration on what happened at the time of crucifixtion, which is quite different from what the christians like to believe. Christ brought the message of God to his people, which was the message of one-ness of God. After he was lifted by Almighty, his followers changed his status. They started calling him the son of God, even though Christ never preached that he is the son of God.
Acording to many scholars the followers of Christ even tempered with the Bible and the word of God, to suit their religious and political whims.
Quran refers to this behaviour as 'unjust', because the followers of christ started associating Jesus as a son of God, thereby deviating from the Oneness of God. Quran says that these were lies created by the followers of Jesus. For a full description of how the Almighty has explained the life and times of Mary and Jesus and the nation of christians, please read the whole of Sura-e-Al-e-Imran (The family of Imran)
Similarly, Quran has explained in length the favors He bestowed on the jews and the way they behaved at later stages. (Read Sura-e-Bani Israel)
All these instances were told in the Quran to make muslims beware that the help of Allah remains with those who remain at the right path. If you deviate from the path of the messangers, then you forsake the favors of God.
You need to read the whole of Quran, as taking isolated examples will bring forth wrong information and reading verses which are out-of-context will only confuse you.
While there will be many others here who will give you quranic references, which you desire, I just felt I should provide a summary of how Quran needs to be studied.
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