'Mission' in the Bible

After they had completed their relief mission, Barnabas and Saul returned to Jerusalem, taking along John who is called Mark.

But while John was completing his mission, he said repeatedly, 'What do you think I am? I am not he. But look, one is coming after me. I am not worthy to untie the sandals on his feet!'

But I consider [my] life [as] worth {nothing} to myself, in order to finish my mission and the ministry that I received from the Lord Jesus, to testify [to] the gospel of the grace of God.