How does Islam view the Christian New Testament?

In Islam, the view of the Christian New Testament is shaped by the understanding that it was revealed to Jesus (known as 'Isa in Arabic) and is considered a part of the divine scriptures. The Qur'an acknowledges this in Surah Al-Maaida, stating: And We caused Jesus, son of Mary, to follow in their footsteps, confirming that which was (revealed) before him in the Torah, and We bestowed on him the Gospel wherein is guidance and a light, confirming that which was (revealed) before it in the Torah - a guidance and an admonition unto those who ward off (evil) 5:46. This indicates that the Gospel, or Injil, is seen as a source of guidance and light for the believers.

However, Islamic teachings also emphasize that over time, the original messages of the previous scriptures, including the Gospel, have been altered or misinterpreted by their followers. This is reflected in another verse: And the Jews will not be pleased with thee, nor will the Christians, till thou follow their creed. Say: Lo! the guidance of Allah (Himself) is Guidance. And if thou shouldst follow their desires after the knowledge which hath come unto thee, then wouldst thou have from Allah no protecting guardian nor helper 2:120. This suggests that the true guidance comes from adhering to the teachings of Allah as revealed to Muhammad, rather than conforming to the altered beliefs of the Jews and Christians.

Overall, while Islam recognizes the Gospel as a divine scripture, it also critiques the current form of the Christian New Testament for having deviated from its original message, and emphasizes the finality of the Qur'an as the ultimate guidance for humanity.