In a contribution to Bild newspaper on Thursday, Erdogan also said Turkey would culturally enrich the EU and not be a burden.
"If the EU wants to limit its 'identity' to Christianity - which I think would be a mistake - what are the millions of people in the EU who aren't Christian going to think?" Erdogan
"I believe that such an act would be detrimental to integration and even have the opposite effect," he said.
EU leaders were poised on Thursday to set a date to start accession talks with Turkey as Erdogan arrived in Brussels in optimistic mood for a spate of last-minute diplomacy.
Turkey is seeking to end over 40 years in the wealthy bloc's waiting room. If the bloc agrees to start talks, they are likely to drag on for a decade or more.
"I believe from the bottom of my heart that the joint interests of Turkey and the EU today are stronger and more interlaced and diverse than they were in 1963," Erdogan wrote in Bild, Germany's top-selling newspaper.
"Turkey has fulfilled all the [EU] requirements and paved the way for a positive decision," he said.
"The decision on Friday reflects not only the status of the political reforms in Turkey, but rather the decision will also make the identity of the EU clearer."
In a separate development, Libyan leader Muammar al-Qadhafi has said it would be dangerous for the European Union to admit Turkey as a member state, calling the accession bid a "Trojan horse" for Islamic "extremists" like Usama bin Ladin.
Al-Qadhafi: Islamic extremists
are rejoicing over Turkey's entry
"As far as the Islamic world is concerned - including the Islamic extremists, even bin Ladin - they're rejoicing over the entry of Turkey into the European Union. This is their Trojan horse," he was quoted as saying by the Italian media.
"I'm saying only what will happen with the entry of the horse into Troy," he added in comments published on the day EU leaders met in Brussels to discuss whether to begin accession talks with the secular but overwhelmingly Muslim Turkey.
Al-Qadhafi made his comments in an interview with RAI television, which is due to be aired on Friday. A transcript was printed on Thursday in Italy's La Repubblica daily.
The Libyan leader said that he did not care whether Turkey was admitted, explaining that he was "only saying what will be the consequences".