Allah says in Surah Yunus:
‘’ O people! There has come to you advice from your Lord, and healing for what is in the hearts, and guidance and mercy for the believers.’’ (Verse 57)
O people! Don't say the Quran fake! Don't say that the Quran was invented by so-and-so! Do not doubt it.
He has given you the advices, exhortations, and instructions you need for the happiness of the two worlds.
It is not a simple book but a revelation from your Lord
It has come as healing to all of your spiritual ailments in your heart.
Whoever believes in the Quran and becomes a Muslim, it will guide that person to the mercy of Allah.