Egypt is a religious country to the core.

Islam is the main religion; Moslems represent about 90% of the total population, while Coptic Christians, and other Christian denominations, form the remaining 10%.

Azhar Mosque, center of Islamic learning of the world

During your tour in Egypt, you won't miss the great number of mosques spread all over the country. Cairo itself was once described as the city of thousand minarets. The number of mosques now is far more than a thousand. You'll find mosques in every area you go.
This indicates what kind of religion-sticking people the Egyptians are.
Among Moslems worldwide, Cairo is their religious capital. This fact is based on the amount of religious studies a Moslem can obtain in the metropolitan city, particularly at Al-Azhar University, the oldest jurisprudential Islamic University in the whole world. Moslems flow from all over the world to Al-Azhar to study more about their religion. If you went to Al-Azhar university, you'll find a diversity of nationalities; the most notable are southeast Asians.

Religious words are uttered by Egyptians so naturally as they talk.
Before they intend to do something they say Insha' Allah (God willing). They also say Alhamdulellah; (Thanks to God) in reply to the question (How are you?) (see Useful Phrases for more information).

Therefore, if you wanted to deal with Egyptian and interact with their society, you have to start learning such words as gestures with them.
There is a religious month called Ramadan, during which Moslems must fast. In that month, people abstain from eating in that month in public places, even the non-Moslem denominations. You also have to follow this as much as possible. However, still many restaurants are open to cater non-Moslems, especially in tourist places, like around the pyramids in Giza.

Saint Mark who brought Christianity to Egypt

Egypt's second faith is Coptic Christianity. Copts are heirs of an ancient Christian rite.
Coptic Christianity was the predominant religion in Egypt until the 10th century when a lot of Christians diverted to Islam. Christianity itself was brought in Egypt by St. Mark in the middle of the first century AD.

Copts are so proud of their faith, as they believe they didn't deviate from the orthodox faith as introduced to the country by early saints.
They got evidences of such claim; Egypt was the cradle of monasticism. It was introduced by Saints Anthony and Pachomius. Other figures also contributed to early Christianity in Egypt like ecclesiastical writers Clement and Origen, and the great Fathers of the Church such as Athanasius and Cyril.

Egypt's role in the Christian world emerges from its steadfastness facing discrimination of heretics.
Today a number of monasteries enrich Egypt's Christian heritage and dot deserts and valleys. A visit to these monasteries will give you an idea about early Christianity in Egypt and the incredible stories of martyrdom of Egyptian saints.