According to court reporters Purnama broke down in tears as he denied allegations that he had insulted Islam.
He was charged with blasphemy earlier this year after footage emerged of him at a political rally apparently claiming that some Muslims have misinterpreted a verse in the Koran which suggests Muslims should not be ruled over by people from other religions.
In his defense at trial, the politician known as 'Ahok' said his comments were addressing politicians who continuously pointed to the verse to suggest that Muslims should not vote for him in the upcoming election.
AFP reported that Ahok's voice cracked as he said in court: "I am very sad, this accusation is the same as saying I have offended my godparents and siblings, whom I love and they love me back."
The governor went on to list all that he had done for his Muslim constituents.
Ahok, who has been in office since 2014, is the first ethnic Chinese to be governor of Jakarta and the first Christian to hold the office in 50 years.
The trial has gripped the Muslim-majority country of Indonesia. Hardline protests attracted hundreds of thousands of protesters chanting "jail Ahok" in November.
Conversely, pro-Ahok protests also brought thousands of Muslim and Christian supporters of the governor onto the streets of the capital.
If Ahok is found guilty, he faces a maximum five-year jail sentence.
The trial was adjourned until 20 December.