Mosques are not the Islamic equivalent of church buildings. They are advance outposts for the spread of Islam, and are inextricably linked to jihad and the political aspect of Islam, which always strives to dominate and subdue whatever territory it enters. This is per the example of the first mosque, which Muhammad established in Medina (cf. The Mosque Exposed, by S. Solomon and E. Alamaqdisi).
For a succinct definition of the significance of the Mosque for Muslims, here is no less an authority than Turkish Prime Minister Recep Tayyip Erdogan:
"The mosques are our barracks, the domes our helmets, the minarets our bayonets, and the faithful our soldiers..."
Piraeus Bishop Asks Court To Stop Mosque
Andy Dabilis - Source: Pravmir
With the Greek government set to construct an official mosque, a leading Greek Orthodox Church leader has asked the country’s highest court to block it as unconstitutional. Bishop Seraphim of Piraeus told the Council of State that the plans violate Article 13 of the Constitution, which stipulates freedom of religious conscience. He said the construction of a mosque should be preceded by an impact study on ethics and public order, the newspaper Kathimerini reported. Seraphim, known for his anti-Semitic remarks*, also told the court that he believes it goes against the constitutional principle of equality, as religious minorities wishing to erect a place of worship in Greece have so far had to apply for a building permit from the authorities. “Building a mosque in the center of Athens will not only damage public order and the morality of Greek society but also trigger a series of events which will, with mathematical certainty, dismantle the cohesion of the Greek nation as a Christian Orthodox people,” he said earlier.
* An article which relates Bishop Seraphim's anti-semitic statements (and his follow-up apology and clarification) may be viewed here. These are deplorable remarks, which I utterly reject. He is also known for some other strong views, which are addressed in the same article. His concern and warning regarding the building of mosques is, however, quite well placed.