John Haluska wrote:Why was the "new" calendar implemented in the mid-1500s;
It wasn't implemented until the 1920's. You are thinking of the Gregorian Calendar in reference to the 1500's. You'd have to ask the Roman Catholics that one- it has nothing to do with me. The proof of this is that the New Calendar and the Gregorian Calendar will no longer be the same after AD 2800. The New Calendarists and the Gregorian Calendarists will never celebrate Pascha and Easter on the same day after AD 2800.
John Haluska wrote:Exactly how did any of these implementations benefit the UNITY of the Orthodox Church?
As stated, there was only one implementation of the New Calendar. It doesn't seem to have effected the unity of the Church except for a small group which has decided to schism over it. The Serbian Patriarchate, the Moscow Patriarchate, the Jerusalem Patriarchate etc all follow the Old Calendar and all managed to stay in Communion with the New Calendarists. It was a small group, in fact only three bishops, who decided they couldn't tolerate it and schismed over it. So perhaps you need to ask the followers of those three bishops how they have benefited Church Unity through schism? If the Church can maintain unity in diversity of customs, why couldn't they?
John Haluska wrote:What was the Orthodox purpose behind the "new" calendar's inception, implementation?
To correct the solar astronomical innacuracies of the Calendar and re-connect it to the realities it was originally meant to reflect. This may come as a shock to many Old Calendarists, but the Earth actually revolves around the Sun, and the date on the Calendar is supposed to reflect Earth's position in it's orbit. The Julian Calendar misplaces the position of the Earth in it's orbit by one day every 128 years. The Revised Julian Calendar, or New Calendar corrects this firstly by correcting the date to match the orbit of the Earth, and the New or Revised Julian Calendar avoids the error the original Julian Calendar makes in the future by not counting the century years which are not divisible by 400 as Leap Years. Thus, the year 2100 will be a leap year for the Old Calendarists, but not for the New Calendarists, and there will thereafter be yet another day's difference between them (14 days). At this rate, by the year AD 3800, the Seasons will all begin a month later according to the Old Julian Calendar, and eventually, Christmas will be celebrated in the Northern Summer and the Southern Winter- And we just don't have any Winter recipes for Christmas food here in Australia.
You may want to ask yourself this: If astronomical accuracy was unimportant to the Fathers of the Church, then why did they decree that the date of Pascha- the Feast of Feasts on the Calendar- should be deterimined by an astronomical event, namely the Jerusalem Vernal Equinox, or the exact time that the sun crosses the elipse in Spring from the point of view of the Church of the Resurrection in Jerusalem?