My mother would like to go back to Greece but she does not have a birth certificate or a passport. She was born in1928 in Kalamata greece and came in 1956 married and has never gone back. Please help it is very important to get her to Greece. Thank you for all your help

If she is Greek Orthodox The Pasteur in the church in Kalamata may be able to help.
Hope you know someone in Kalamata it would be easier.That person can help you. He can talk to the Pasteur or government registry, family registry, municipality.
You can also find info's at the embassy or consulate of Greece in your area They will tell you about a procedure to follow.
Hope this help.

My mother would like to go back to Greece but she does not have a birth certificate or a passport. She was born in1928 in Kalamata greece and came in 1956 married and has never gone back. Please help it is very important to get her to Greece. thank you for all your help

How did she get into the US (assuming, of course, she is in the US) in 1956? The State Department, who she would have to contact for a passport anyway, should have some record of her immigration.