Prophet Muhammad explained in the Hadith about intercession that no one will be brought out of Hell except those who died believing in Tawhid and uttered the Shahadah and had in their hearts something of faith.

The Quran is the Word of Allah, and the Quran is one of the attributes of Allah. So if a person says “By the Quran” or “By the life of the Quran”, there is nothing wrong with that.