Here we see the interior of the Hagia Sophia, in Istanbul. The Muslim Ottoman Turks conquered Constantinople in 1453 and changed the church into a Mosque. In the late 1800s and early 1900s, it was changed to a Museum.
Notice the icon of Mother Mary and baby Jesus; and the Arabic sign “Allah” near by. The icons were plastered over for centuries; only in recent years were the icons restored. When the Muslims heard Christians calling Mary, “the Mother of the God”; they thought the Trinity was “The Father, the Son, and the Mother”.
Ever since I first started witnessing the gospel of Jesus Christ to Muslims, many Muslims have said to me, “If you call God “the Father”, and Jesus “the Son of the God”, then there must be “mother”; and this is Mary and we have seen the Christians praying to her and bowing down in front of her statue and picture; this is a blasphemy and idolatry and paganism; and the Qur’an confirms this is what you believe about this Trinity thing.” Calling her “the Mother of the God” (Which Roman Catholics do) confirms your idolatry for us!” (Qur’an 5:116; 5:72-73) See also, Qur’an, Surah 6:101/102
The church had neglected and long since left its first love (Rev. 2:4-5); so God allowed Islam to judge and conquer many areas of the early church. The church slowly drifted and neglected their Biblical love relationship with Jesus; drifted from sound doctrine; added man-made traditions; fought with themselves over territories and were plagued with political intrigue; neglected evangelism and missions. The Chalcedonian Orthodox (those that agreed with the sound doctrine of the Council of Chalcedon in 451 AD) and Byzantine (under Emperors Theodosius (380-392 AD), Justinian (527-565 AD), and Heraclius (610-641 AD) – these Emperor’s methods and the sending of soldiers into their areas, were too harsh against Monophysites (Egyptian Coptic Church, Jacobite Syrian Church, Armenians) and Nestorians. The wars of Persia and Rome(Byzantine) left a vacuum for Islam to fill; then the aggressive Jihad wars of Islam came and filled that void; and the heretical and nominal Christians in the east and the desert influenced Muhammad and gave him a wrong impression of what Christianity is. He misunderstood the doctrine of the Trinity and what we mean by “Son of God” and calling God “Our Father”. The visible practices of Roman Catholics and Eastern Orthodoxy to this day still give Muslims the wrong impression about Christian doctrine. The harshness of the Byzantine policies in Egypt and the Levant areas caused a lot of the eastern Christians to welcome the Muslims at first, as liberators from their Byzantine oppressors. Later, the Coptic Church and the Syrian Orthodox Church realized it was too late. The Islamic Dhimmi system, the Caliphate, the Jiziye tax, and lack of freedom to evangelize or build new churches oppressed the Christian and Jews living in Muslim lands; so that eventually, many converted to Islam over the subsequent centuries. But that proved that they were not true believers. They had become dead ritualistic churches that compromised the truth of the gospel. Like Israel of old, “Another generation arose after them that did not know the LORD.” (Judges 2:10)