There is no doupt that ancient Macedonians were Greek. It is thoroughly proved by historic documents and archaeological discoveries which can be found in history books and museums in Greece and arround the world. The most important archeological discovery in Macedonia is the tomb of King Philippos II. It was excavated in Vergina, Greece in 1978 and it proves beyond any doubt the Greekness of ancient Macedonia. All the findings are characteristic of the Greek culture and all the inscriptions are written using the Greek language. Among the discoveries of this tomb is the "Vergina sun" the symbol that FYROM attempted to use on its flag initially.
Facts which prove that ancient Macedonians were Greek people:
Macedonians spoke a dialect of the Greek language
All the monuments and inscriptions found in the Macedonia are written using the Greek language. Take a look at the archaeological discoveries. There is no historic evidence to suggest that the Macedonians were using a different language.
Macedonians had Greek names
All the ancient Macedonian names mentioned in history or found on tombs are Greek. All the kings of Ancient Macedonia had Greek names. Nobody discovered ancient Macedonian names ending to -ov or -ovski or whatever.
Alexander's name is Greek. The word "Alexandros" is produced from the prefix alex(=protector) and the word andros(=man) meaning "he who protects men". The prefix "alex" can be found in many Greek words today (alexiptoto=parachute, alexisfairo=bulletproof - all these words have the meaning of protetion).
Philip's name is also Greek. It is produced from the prefix Philo(=friendly to something) and the word ippos(=horse) meaning the man who is friendly to horses. The prefix "philo" and the word "ippos" are also found in many words of Greek origin today (philosophy,philology, hippodrome,hippocampus).
A detailed list of ancient Macedonian names can be found here.
The regions of ancient Macedonia had Greek names.
The regions which formed ancient Macedonia had Greek names. Most of these names are used in Greece even today.
Macedonian architecture was similar to the Greek architecture.
All the buldings found in the Macedonia region have many common characteristics with the ones found in the rest of Greece. Palaces, temples, theaters markets are characteristic sampes of ancient Greek architecture.
Macedonians fought together with the rest of the Greeks.
Macedonians always fought along with the other Greek city-states against enemies from Asia.
Macedonians took part in the Olympic games.
It is well known then ONLY Greeks were allowed to take part in the ancient Olympic games. For a list of Macedonians who participated in the Olympic Games.
Macedonians celebrated the same festivals as the rest of the Greeks.
Examples of festivals which were celebrated in Macedonia as well as in other Greek states are the "Hetaireidia", the "Apellaia" and many more.
Macedonians worshiped the same Gods as the rest of the Greeks.
Several temples dedicated to the Greek Gods have beem discovered in Macedonia and especially in Dion the religious center of ancient Macedonians. It is obvious that the Macedonias worshiped the 12 Olympian Gods as the rest of the Greeks. The Gods were "living" on Mount Olympos which happens to be located in Macedonia.
How would that be possible if there was hostility between Macedonians and Greeks?
This is another proof that Macedonia was considered a part of Greece.
FYROM's residents have no historical cultural or linguistic ties with ancient Macedonia.
The heart of ancient Macedonia was not in the teritory which FYROM occupies but in the Greek part of Macedonia were all the major archaeological discoveries took place.
The name "Republic of Macedonia implies a teritorial threat against Greece and other countries and it creates a great risk of renewed ethnic conflict in the Balkans.