The leader of the 7 July 2005 bombers was Mohammad Sidique Khan who made a pre-suicide videotape; the link takes you to the text of the video. I don't believe that a man recording a video before committing suicide will lie about his motivation and have selected the following extract:
"Our religion is Islam - obedience to the one true God, Allah, and following the footsteps of the final prophet and messenger Muhammad... This is how our ethical stances are dictated. Your democratically elected governments continuously perpetuate atrocities against my people all over the world. And your support of them makes you directly responsible, just as I am directly responsible for protecting and avenging my Muslim brothers and sisters."
His videotape states clearly that he was motivated by his religious beliefs and not by some other aspects of his identity. We all have multiple identities; I am simultaneously British, Mancunian, Punjabi, Pakistani, Muslim, Conservative and Cantabrigian amongst others. Different aspects of my identity come to the fore in different contexts. Mohammad Sidique Khan's statement makes it clear that he was motivated primarily by his religious beliefs and not by some other aspect of his identity.