The Great Commission is to evangelical Christians the basis for their worldview and activities arising from it. It is also more generally the primary basis for Christian missionary activity in general. It is given most explicitly in Mark 16:15-16: "Go ye into all the world and preach the gospel unto every person. He that believeth and is baptised shall be saved; he that believeth not shall be damned." This quotation from Jesus suggests that all his followers as Christians have this duty to do, although it was given directly only to his apostles.

Critics note that this portion of Mark 16 is not found in two of the oldest Greek manuscripts of the New Testament, the Codex Vaticanus and the Codex Sinaiticus. The response generally given is that this is immaterial, as essentially the same thing is quoted as having been said by Jesus in at least three other New Testament passages, and that additionally, the passage in question has always been regarded as part of the canon of the scriptures by church leaders of all ages from the 1st century CE to the present.

Evangelicals often contrast this "Great Commission" with the "Limited Commission" given to seventy of Jesus' followers as reported in Luke 10, in which they were to restrict their mission to their fellow Jews, to whom Jesus referred as "the lost sheep of the house of Israel".

Most Christian missionary and religious conversion activities are products of the Great Commission being interpreted as being valid and binding upon all Christians of all eras, not just the 1st century apostles.