There are three possibilities with the Great Commission. You can go. You can send. Or you can be disobedient. Ignoring the cause is not a Christian option. If we love God’s fame and are committed to magnifying his name above all things, we cannot be indifferent to world missions. Over and over we read this in the Bible — that God does what he does so “that [his] name might be proclaimed in all the earth.” (Romans 9:17) The central command of missions is Isaiah 12:4, “Make known his deeds among the peoples, proclaim that his name is exalted.”
—John Piper
Brothers, We Are Not Professionals: A Plea to Pastors for Radical Minstry
Related: Passage for March from the 2008 Desiring God Calendar.