How was the Holy Quran transmitted in detail, and why do doubts arise about it despite its transmission from generation to generation, and how can a Muslim find peace in their heart and have strong faith?

The Holy Quran has been characterized by care, documentation, preservation, and scrutiny since its revelation. It has been preserved exactly as the Prophet, peace and blessings be upon him, recited it. This is a fulfillment of Allah's promise in His saying: {Indeed, it is We who sent down the Dhikr (the Reminder), and indeed, We will be its guardian.} The Quran was preserved during the Prophet's era through various means, such as the descent of revelation, the angel's study with the Prophet, the writing of the revelation, the encouragement to learn the Quran, and the strong memory of the Arabs. Then, the Companions committed to preserving it after the death of the Prophet, peace and blessings be upon him. Abu Bakr al-Siddiq collected it after the death of many memorizers, and Uthman ibn Affan unified the masahif (copies of the Quran) to the dialect of Quraysh due to differences in languages. The Quran reached us through tawatur (multiple independent chains of transmission), both in wording and recitation, which conveys certain knowledge and makes it impossible for its transmitters to conspire in falsehood. This is completely different from the Gospels, which were not written during the time of Christ and whose versions contradict each other. As for equating the Quran and the Gospel in terms of isnad (chain of narration), transmission, and authenticity, this is false due to the lack of evidence.