Oldest church ( 52 AD )- The Palayur Church built by St. Thomas,Kerala, India

52 AD StThomas syro-Malabar church, Palayur, Kerala flickr.com
The Palayur Church,also known as  St Thomas Syro-Malabar Catholic Church, is a tourist favorite near Guruvayur - 13 km from the Railway station. Located at Palayur (also spelt Palayoor), in Thrissur district of Kerala on the west coast of India this church was established in 52 AD  by St. Thomas, an apostle of Jesus Christ.  It is the oldest church in India and is called an Apostolic Church credited to the Apostolate of St. Thomas who  not only preached and but also started conversion of people to Christianity here.Out of seven churches built by the noted Apostle, this church is one of them. 
This church depicts the life and work of St. Thomas. There are about fourteen granite idols in the church that portray the life and work of the Apostle at different stages. These statues can be seen at the entrance of this church. The Hindu king in Kerala gave St. Thomas enough lands to build churches in various places and this shows the presence of Christianity in ancient India.
During the celebration of the Palayur Mahatheerthadanam festival, devotees from every nook and corner of India come here carrying a wooden cross. Muppittu Njayar, Thukharana Thirunal and Tharpana Thirunal are other important events conducted at the Palayur Church. Newborn babies are brought to this church on Muppittu Njayar for baptizing.

52 AD St.Thomas syro-malabar church, old interior flickr.com
The original small Church structure is retained at the oldest site.Without sacrificing the main sanctity of the place substantial improvements around it were carried out during the 17th century by Rev. Fenichi

Church History Association of India (1969). Indian Church History Review, Volume 3 (1969 ed.). Church History Association of India.