Praise be to Allah.
If Allah enables someone to memorize His Book, seeking His pleasure thereby, and not seeking any worldly gain thereby, then he is one of those for whom Allah wills good, in sha Allah.
The Qur’an is the foundation of Islamic knowledge. The Prophet (blessings and peace of Allah be upon him) said: “The best of you are those who learn the Qur’an and teach it.” Narrated by al-Bukhaari (5027).
Muslim (804) narrated that Abu Umaamah al-Baahili said: I heard the Messenger of Allah (blessings and peace of Allah be upon him) say: “Read the Qur’an, for it will come on the Day of Resurrection interceding for its companions.”
But the one who memorizes the Qur’an then goes against its rulings and does not observe its etiquette should beware, lest the Qur’an be evidence against him and not for him.
Muslim (223) narrated that Abu Maalik al-Ash‘ari said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “the Qur’an is evidence for you or against you.”
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said:
It will either be for you, if you draw near to Allah by means of it, and fulfil the duties prescribed by this great Qur’an, namely believing its stories, complying with its commands, heeding its prohibitions, and venerating and respecting this Holy Qur’an – in this case it will be evidence for you;
or if it is the opposite – if you disrespect the Qur’an and neglect its phrases and meanings, and fail to act in accordance with it, and do not do what it enjoins, then it will be a witness against you on the Day of Resurrection.
End quote from Sharh Riyadh as-Saaliheen (p. 30).
And Allah knows best.