Entering churches for meetings and to listen to lectures is not free of a number of haraam things, some of which have been discussed in the answer to question no. 82836.
The scholars differed concerning the ruling on a Muslim entering a church in the first place. There are a number of opinions:
That it is haraam. This is the view of the Hanafis and Shaafa’is, but the Shaafa’is limit the prohibition to churches in which there are images, as it says in Tuhfat al-Muhtaaj (2/424), Nihaayat al-Muhtaaj (2/63) and Haashiyata Qalyoobi wa ‘Umayrah ‘ala Sharh al-Muhalla (4/236).
The Hanafis regard it as haraam 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-Raa’iq (7/364) and in Haashiyat Ibn ‘Aabideen (2/43).
That it is makrooh. 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 Allaah have mercy on him) said in al-Fataawa al-Kubra (5/327): The view which most of our companions hold is that it is makrooh to enter churches in which there are images, and this is the correct view concerning which there can be no doubt. End quote.
See: al-Furoo’ (5/308), al-Adaab al-Shar’iyyah (3/415) and al-Insaaf (1/496).
They quoted the following as evidence:
It was narrated from Ibn ‘Abbaas (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah 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-Bukhaari (3352).
It was narrated that Ibn ‘Umar (may Allaah be pleased with him) said: Jibreel promised to come to the Prophet (peace and blessings of Allaah be upon him) but he was late and the Prophet (peace and blessings of Allaah be upon him) grew concerned. The Prophet (peace and blessings of Allaah 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-Bukhaari (5960).
It was narrated that 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-Razzaaq in al-Musannaf (1/411 and 10/398).
3 – The third view is that 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-Insaaf (1/496).
It is also the view of Ibn Hazm al-Zaahiri as it says in al-Muhalla (1/400).
They quoted the following as evidence:
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.
Ibn ‘Aa’idh narrated in Futooh al-Shaam 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 the Ameer al-Mu’mineen entered this place?
By studying the evidence quoted above, it does not seem that there is any clear evidence that it is haraam to enter churches. The fact that there are images and statues in them or any other place does not mean that it is haraam 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 Qudaamah (may Allaah have mercy on him) said:
With regard to entering a house in which there is an image, it is not haraam. 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. End quote.
But at least it is makrooh to enter churches unnecessarily, because the fact that the angels and the Prophet (peace and blessings of Allaah be upon him) did not enter the house in which there were images indicates that it is makrooh.
Moreover this being makrooh may reach the level of being haraam if entering the church will lead to any bad consequences such as if it means approving of the Christians’ shirk and their claim that Allaah has a wife and son, exalted be Allaah 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 Fataawa al-Lajnah al-Daa’imah (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. End quote.
See also the answer to question no. 11232.
And Allaah knows best.