Open Doors, an anti-persecution charity, made contact with Mohammed, which is not his real name, after he learned about the Bible on the internet and left Islam, the religion he was born into.
Leaving Islam is punishable by death in Saudi Arabia.
No believers have been executed for the offence but some have been reported to their families and later vanished.
Mohammed took a course supported by Open Doors.
Saudi Arabia:
Leader: King Salman
Population: 32.2 million - 1.4 million Christians
Main Religion: Islam
Government: Monarchy
World Watch List Rank: 14
He later made contact with some Christians in another country in the Middle East through a Christian website aimed at the Arab community.
He sent them a message asking to meet and was invited to visit them.
Mohammed travelled to another country and attended church where he was given a Bible, he also went to study classes.
He was also baptised and returned to Saudi Arabia with a Bible.
He told his wife he was on a business trip, however, she found the Bible and questioned it.
Open Doors says that Mohammed said it was a gift and he wanted to read it as the Quran names the Bible as one of the holy books of Islam.
His wife asked him: "When you are finished with the Bible, can I read it too?"
Mohammed has not met another Christian in Saudi Arabia, but has made friends over the internet.
It is thought that satellite TV and the internet are enabling Saudis to hear about the Christian faith.
