In calling non-Muslims to Islam, the non-believer is not convinced by the words of Allah and His Messenger

The questioner : A few days ago, there was a discussion where we spoke about this matter, excuse me, after the Fajr prayer: that even when you call people and say, "Allah said so" or "His Messenger (peace and blessings be upon him) said so," a group of young men who were studying in institutes and colleges said that some Christians, if you argue with them using a verse or a hadith, they are not convinced. So what is the ruling in this case? I mean, if you tell him the verse, that Allah said such and such, and the Messenger (peace and blessings be upon him) said such and such, he does not accept it, but says, "I need a proof from reason." What is your opinion?

The Shaykh : The Shari'ah contains all good.

The questioner : May Allah reward you.

The Shaykh : And it is not permissible to use as evidence anything other than the Book and the Sunnah.

The questioner: Yes.

The Shaykh : The established ones, because the Book and the Sunnah contain both transmission and reason together.

The questioner : Yes, do you reside in al-Ra's al-'Ayn?

The Shaykh : Al-Ra's al-'Ayn.

The questioner : Yes, with a group of visitors?

The Shaykh : What do you do?

The questioner : I used to work in a private commercial company, and now the company has closed, so I started a second job, praise be to Allah, a job in mobile phones and trade. May Allah grant us success in what He loves and is pleased with. But the primary goal that made me apply here is to obtain knowledge, especially from you, O Shaykh.

The Shaykh : And originally from Iraq?

The questioner : Yes, that is right.

The Shaykh : From which part?

The questioner : From Diyala Governorate, north of Baghdad.