Damascus has a special place in early Christianity, through its connection to St. Paul and his conversion to Christianity. According to the Book of the Acts of the Apostles, St. Paul encountered Christ on the road to Damascus. Once he was there, he was baptized by one of its citizens, St. Ananias. He later made a dramatic escape from the city. 

After his vision on the road to Damascus, St. Paul entered went to the main street of Damascus, the Via Recta (the “Straight Street”) that runs from east to west. As the Book of  the Acts of the Apostles records:

And the Lord said unto him [Ananias], Arise, and go into the street which is called Straight, and inquire in the house of Judas for one called Saul, of Tarsus: for, behold, he prays.

This street was built during the Hellenistic Era when Damascus was redesigned with a grid plan.  

Near the end of Via Recta, there is a church known as the House of St. Ananias. It is traditionally considered to be the house of St. Ananias, who baptized St. Paul. St. Ananias is traditionally considered to be one of the 70 disciples as well as being the first bishop of Damascus. Archaeological excavations in 1921 found the remains of a Byzantine church from the 5th or 6th century CE, adding physical evidence to support local tradition that the chapel has an early-Christian origin. 
The Chapel of St. Paul is a modern stone chapel in Damascus that incorporates materials from the Bab Kisan, the ancient city gate through which Paul was lowered out of a window, as recorded in the Book of Acts. In Paul's time, the city of Damascus was surrounded by a wall pierced by seven gates. Bab Kisan is the gate on the southeastern side of Damascus and was dedicated to Saturn.  This southeastern district of the city was not only very close to the start of the Roman road that St. Paul would likely have taken, but was also the part where, from the earliest times, the Christians used to live. Early Christian tradition identified a window beside the Kisan Gate, as the window from which St. Paul was lowered.

According to tradition, St. Thomas was also a resident of Damascus for a period. Bab Touma – the Gate of Thomas – is the entrance to the Christian quarters of the old city.