By the BBC's James Reynolds in Jerusalem
The issue of land ownership is vital in many places in the world - not least in the Middle East between the Israelis and the Palestinians.
There is one dispute in Israel which may affect this. The Israeli Government is refusing to recognise the new head of the Greek Orthodox Church in Jerusalem, Patriarch Irenaios.
This is an important move because the Church is a key landowner in Israel and the West Bank.
The Israelis feel he's a supporter of the Palestinian issue and of the Arabs in general
Journalist Danny Rubinstein
Patriarch Irenaios worries the Israelis. They feel he is too independent, too eager to make friends with Palestinian leader Yasser Arafat, and even a security threat.
"The Israelis don't like the fact that he's leaning on the Palestinian side," says Danny Rubinstein, from the Ha'aretz newspaper.
"They feel he's in a close relationship with Arafat, that he's a supporter of the Palestinian issue and of the Arabs in general."
The Israelis fear this may affect the patriarch's decisions on the vital issue of land. The Greek Orthodox Church owns large amounts of land here - in both Israeli and Palestinian areas.
This is land it has owned - in some cases - for hundreds of years and which is extremely important. It includes the land around Israel's parliament - the Knesset.
Land around the Knesset is owned by the church
One of the new patriarch's first moves has been to check the use of this land and all other church land, something which alarms Israel.
But the Greek Orthodox Church here says it does not want to make life difficult for the Israelis. It simply wants to know what is happening on its land.
"We don't know exactly," says Archbishop Aristarchos of the Greek Orthodox Patriarchate.
"And we should know through our advocates whether or not our leases have expired, whether or not we are paid rents and so on. This is the spirit of the decision."
This decision may have consequences for a group of Israelis in Jerusalem's Old City.
They live in a church building - in the middle of a mainly Palestinian area.
They have placed an Israeli flag out of the window - and guards with flak jackets stand inside the front door.
Those in the house do not want to talk about the new patriarch. Nor do Israeli officials.
The Israeli-Palestinian conflict is a fight for the possession of land. A clergyman from Greece may have some say in how it goes.