The honest answer is that the Quran does support our method, but not always by giving a one-line verse for every detailed ruling. It gives principles, commands obedience to the Prophet (PBUH), and then the Sunnah and sound scholarship explain and apply those principles.
Why the question is a fair one
The strongest form of the challenge is this: "If you say Islam teaches a certain belief or rule, show where the Quran supports it. Do not hide behind later custom, culture, or scholarly authority if the Book of Allah does not actually say it."
That is a reasonable demand. Muslims should not attribute things to Allah without evidence. The Quran itself criticizes people who speak about Allah without knowledge. So if someone asks, "Which verses support your stance?", the answer should not be evasive.
The Quran gives the framework, not just isolated slogans
The Quran repeatedly tells believers to obey Allah and obey the Messenger. That means the Prophet Muhammad (PBUH) is not merely a mailman who delivered the text and then disappeared from religious authority. He taught, explained, judged, and lived the revelation.
"O you who believe, obey Allah and obey the Messenger and those in authority among you. And if you disagree over anything, refer it to Allah and the Messenger, if you should believe in Allah and the Last Day."
Quran 4:59
"And We revealed to you the message that you may make clear to the people what was sent down to them and that they might give thought."
Quran 16:44
"And whatever the Messenger has given you, take; and what he has forbidden you, refrain from."
Quran 59:7
These verses establish a major point: Quranic support is not limited to verses that spell out every detail in isolation. The Quran itself directs us to the Prophet's (PBUH) explanation and authority.
How scholars use the Quran responsibly
Classical scholars did not simply pick a verse that sounded useful. They read the Quran as a whole, together with authentic hadith, the Arabic language, the practice of the early Muslims, and the principles of law. They asked: Is a verse general or specific? Is it absolute or qualified? Is there another text explaining it? How did the Prophet (PBUH) apply it?
This is why many rulings are firmly Islamic even if their full detail is not contained in a single verse. The Quran commands prayer, but the number of rak'ahs and the form of prayer are known through the Prophet's (PBUH) teaching. The same is true for many matters of worship, law, and ethics.
"There has certainly been for you in the Messenger of Allah an excellent example for whoever hopes in Allah and the Last Day and remembers Allah often."
Quran 33:21
What this proves, and what it does not prove
What it proves is that a Muslim stance may be Quranic either directly, through an explicit verse, or indirectly, through the Quran's command to follow the Prophet (PBUH) and the revealed method of interpretation.
What it does not prove is that any random claim becomes Islamic just because someone attaches a verse to it. A specific stance still needs specific evidence. If the issue is a belief, a moral teaching, or a legal ruling, then the relevant verses, authentic hadith, and scholarly reasoning must be presented clearly.
So the best answer to "Which verses of the Quran support your stance?" is: show the direct texts where they exist, show the Quranic authority for the Sunnah where details come through the Prophet (PBUH), and be honest about the strength and limits of the evidence.