Quo vadis? is a Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 phrase meaning "Where are you going?" or "Whither goest thou?" The modern usage of the phrase refers to Christian

Christian

A Christian is a person who adheres to Christianity, an Abrahamic, monotheistic religion based on the life and teachings of Jesus of Nazareth as recorded in the Canonical gospels and the letters of the New Testament...

 tradition, related in the apocryphal Acts of Peter

Acts of Peter

The Acts of Peter is one of the earliest of the apocryphal Acts of the Apostles. The majority of the text has survived only in the Latin translation of the Vercelli manuscript. It is mainly notable for a description of a miracle contest between Saint Peter and Simon Magus, and as the first record...

 (Vercelli Acts XXXV), in which Saint Peter

Saint Peter

Saint Peter or Simon Peter was an early Christian leader, who is featured prominently in the New Testament Gospels and the Acts of the Apostles. The son of John or of Jonah and from the village of Bethsaida in the province of Galilee, his brother Andrew was also an apostle...

 meets Jesus

Jesus

Jesus of Nazareth , commonly referred to as Jesus Christ or simply as Jesus or Christ, is the central figure of Christianity...

 as Peter is fleeing from likely crucifixion in Rome. Peter asks Jesus the question "Quo vadis?" Jesus's answer, "I am going to Rome to be crucified again" (Romam vado iterum crucifigi.), prompts Peter to gain the courage to continue his ministry and eventually become a martyr.

The phrase also occurs a few times in the Vulgate

Vulgate

The Vulgate is a late 4th-century Latin translation of the Bible. It was largely the work of St. Jerome, who was commissioned by Pope Damasus I in 382 to make a revision of the old Latin translations...

 translation of the Bible

Bible

The Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...

, notably in John

Gospel of John

The Gospel According to John , commonly referred to as the Gospel of John or simply John, and often referred to in New Testament scholarship as the Fourth Gospel, is an account of the public ministry of Jesus...

 13:36, when Peter also asks the question of Jesus after which Jesus announces he is going to where his followers cannot come.