Can Muslims Go to Church?
Question

What is the ruling on a Muslim entering a church to listen to a lecture that is being given there?
Praise be to Allah.Scholarly views on Muslims going to churches
The scholars differed concerning the ruling on a Muslim entering a church in the first place. There are a number of opinions: 
It is haram for Muslims to go to churches
This is the view of the Hanafis and Shafi’is, but the Shafi’is limit the prohibition to churches in which there are images, as it says in Tuhfat al-Muhtaj (2/424), Nihayat al-Muhtaj (2/63) and Hashiyata Qalyubi wa ‘Umayrah ‘ala Sharh al-Muhalla (4/236). 
The Hanafis regard it as haram in all cases, and they gave as their reason the fact that they are abodes of the devils, as the Hanafi Ibn Nujaym said in al-Bahr al-Raiq (7/364) and in Hashiyat Ibn 'Abidin (2/43). 
It is makruh for Muslims to go to churches
This is the view of the Hanbalis, but some of them limited this to churches in which there are images. Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said in al-Fatawa al-Kubra (5/327): “The view which most of our companions hold is that it is makruh to enter churches in which there are images, and this is the correct view concerning which there can be no doubt.” (See, al-Furu’ (5/308), al-Adab al-Shar’iyyah (3/415) and al-Insaf (1/496) 
They quoted the following as evidence:  
(1) Ibn 'Abbas (may Allah be pleased with him) narrated that the Prophet (peace and blessings of Allah be upon him) saw images in the Ka’bah and he did not enter until he had ordered that they be erased. Narrated by al-Bukhari (3352). 
(2) Ibn ‘Umar (may Allah be pleased with him) said: Jibril promised to come to the Prophet (peace and blessings of Allah be upon him) but he was late and the Prophet (peace and blessings of Allah be upon him) grew concerned. The Prophet (peace and blessings of Allah be upon him) went out and saw him, and he told him of his concern and he said to him: “We [angels] do not enter a house in which there is an image or a dog.” Narrated by al-Bukhari (5960). 
(3) Aslam, the freed slave of ‘Umar, said: When ‘Umar went to Syria, one of the leaders of the Christians made food for him and called him. ‘Umar said: We will not enter your churches because of the images that are in them – meaning the statues. Narrated by ‘Abd al-Razzaq in al-Musannaf (1/411 and 10/398). 
It is permissible to enter churches in general
This is the view of the Hanbalis, as it says in al-Mughni (8/113) and al-Insaf (1/496). 
It is also the view of Ibn Hazm al-Zahiri as it says in al-Muhalla (1/400). 
They quoted the following as evidence: 
(1) What was narrated about the conditions stipulated by ‘Umar to the people of the Book to expand their churches and monasteries so that the Muslims could enter them to spend the night or pass through them. Al-Mughni (8/113). 
(2) Ibn ‘Aidh narrated in Futuh al-Sham that when ‘Umar came to Syria, the Christians made food for him and called him, and he said: Where is it? They said: In the church, and he refused to go. He said to ‘Ali: Take the people to eat lunch. So ‘Ali took the people and entered the church, and he and the people ate lunch, and ‘Ali looked at the images and said: What would be wrong if Amir al-Mu’minin entered this place? Al-Mughni (8/113). 
By studying the evidence quoted above, it does not seem that there is any clear evidence that it is haram to enter churches. The fact that there are images and statues in them or any other place does not mean that it is haram to enter it. The sin is on the makers of the images and those who make the statues; the one who enters a place where those statues are should advise and explain, but he does not have to leave that place. 
Ibn Qudamah (may Allah have mercy on him) said: 
“With regard to entering a house in which there is an image, it is not haram. Rather it is permissible to refuse an invitation because of it as a rebuke to the host and to show that he has lost respect because of his introducing something evil into his house. The one who sees it in the host’s house does not have to leave, according to the apparent meaning of Ahmad’s words. He said, according to the report of al-Fadl: If he sees an image on the curtain that he did not see when he entered, that is less serious than if it was on the wall. It was said: If he did not see it until the food was placed before them, should he leave? He said: Do not make things too difficult for us; but if he sees it he should rebuke them and tell them not to do that.” Al-Mughni (8/113) 
But at least it is makruh to enter churches unnecessarily, because the fact that the angels and the Prophet (peace and blessings of Allah be upon him) did not enter the house in which there were images indicates that it is makruh. 
Moreover this being makruh may reach the level of being haram if entering the church will lead to any bad consequences such as if it means approving of the Christians’ shirk and their claim that Allah has a wife and son, exalted be Allah far above that. Or if entering the church is a sign of taking the Christians as friends and loving them, and so on. 
It says in Fatawa al-Lajnah al-Daimah (2/115): 
“If your going to the church is just to show tolerance and lenience, then it is not permissible, but if it is done to call them to Islam and create opportunities for you to do so, and you will not be taking part in their worship and you are not afraid that you may be influenced by their beliefs or customs, then it is permissible.”
 For more about church related issues, please see these answers: 2189  , 1833 , 269272 , 147007 , and 2132
And Allah knows best.