"Christmas is a day and a holiday of joy, a holiday of kindness and love and understanding of all people, regardless of their denomination and the tradition they belong to," said the president.
He praised the atmosphere at the service, saying the last time he attended such a joyous Mass was in Washington, also in a Baptist church.
Pastor Zdenko Horvat thanked the president for attending, saying it was a great honour for the Baptist Church and its faithful.
The Baptist Church has existed in Croatia more than 100 years. It has about 2,500 members and about 50 churches around the country, including three in Zagreb.