Why become a Christian?
Mission must spring from a lead back into a quality of life which seems intrinsically worth having in itself. If we answer the question “why should I become a Christian?” simply by saying “In order to make other Christians,” we are involved in infinite regress. The question “to what end?” cannot simply be postponed to the eschaton…the life in Christ is not merely the instrument of the apostolic mission, it is also its end and purpose.
-Lesslie Newbigin, The Household of God, 147.