(Before It's News)
The Qur’an affirms the inspiration (3:3-4), preservation (7:157; 18:27), and authority of the Gospel (5:47, 68). Yet our Muslim friends tell us that the Gospel has been corrupted. Here we may start to wonder who corrupted it. According to the Qur’an, Jesus never died by crucifixion (4:157-158). According to the Bible, Jesus died by crucifixion (e.g., Matthew 17:22-23; 27:50; etc.). Who corrupted the portion of the Gospel that reports Jesus’ death on the cross? Interestingly, Islam teaches that Allah corrupted the Gospel by tricking and deceiving people into believing that Jesus died on the cross. But why would Allah corrupt his own revelation?
Source:
http://www.answeringmuslims.com/2014/02/why-did-allah-corrupt-gospel.html