Why do ministry? Why share the gospel? Why lead congregations? Why take part?
Here’s one answer from John, at least as to why he proclaims Jesus Christ:
That which we have seen and heard we proclaim also to you, so that you too may have fellowship with us; and indeed our fellowship is with the Father and with his Son Jesus Christ.
-1 John 1:3
This all sounds pretty circular if we misunderstand (as many do) what the word “fellowship” meant the apostles. If “fellowship” just means getting together and being pals, then it seems like John is saying “I’m inviting you to the club so we can have a club.” This might lead them (or us) to ask “Then why should I choose the Church? Why not be part of a club that also reads books or rides bikes or tastes wine?”
However, getting together and being pals is just one part of “fellowship.” Consider this attempt at a definition for the Greek word behind it, koinonia:
…koinonia [is] one of those untranslatable words for which “fellowship” provides one angle, “business partnership” another, and “family solidarity” a third, still leaving us with a sense that more needs to be said for the whole to be grasped.
-N.T. Wright, Paul and the Faithfulness of God, p.401
Yes, John proclaims the Christ because he wants us to share the fellowship that is gathered around Jesus, but that’s not the whole of it. This koinonia is also a mission, also an opportunity to belong, and a great deal more besides. Indeed, the invitation to koinonia is an invitation to fellowship, mission, and belonging, not only with God’s people, but also fellowship, mission, and belonging with God Himself. In other words, we don’t welcome people into congregations simply because “everyone needs a thing”; rather, we proclaim Jesus Christ because in Jesus Christ we discover who we are mean to be, what we are to do, and those with whom God is empowering us to be and do it.
Ultimately, everyone does “need a thing,” this thing: Fellowship with the Father and His Son Jesus Christ, a fellowship we’ve somehow been drawn into and that we long for others to enjoy.