How to deal with those who claim to be Muslim but do not know the reality of Islam?

The questioner:
A questioner from Russia says: It is well known that our country was under communism for more than seventy years, and now, praise be to Allah, the religion of Islam has spread. However, many of those who claim to be Muslim do not know the reality of Islam, and they believe that it is merely faith in Allah, His angels, and His books.

The Shaykh:
The negligence of the Muslims. It is obligatory for the Muslims to go to them, teach them, and guide them. They must explain this to them; this is the duty of the Muslims. Their Muslim brothers go to them and teach them. They study Islam with them. Yes.

The questioner:
Then he says, in the continuation of his question: How do we deal with them, and do we eat from our scholars?

The Shaykh:
They bring students from them to study in the universities. The universities of Shari'ah. Tawhid (the oneness of Allah), 'aqidah (creed), fiqh (Islamic jurisprudence), hadith, and tafsir (Qur'anic exegesis). They return to their countries. They call to Allah. This is necessary. The Muslims do not neglect them. The Muslims do not neglect their brothers. They leave them to ignorance. Yes.

The questioner:
Then he says, in the continuation of his question: How do we deal with them? Do we eat their slaughtered animals? Do we marry their women? Do we follow their funeral processions?

The Shaykh:
As long as they display Islam and claim to be Muslim, and they have ignorance, and they are Muslims, they are treated as Muslims. But they are not left to be neglected; it is necessary to explain to them, study Islam with them, and clarify this to them. Yes.