Or how about this, Ephesians 4:11-12 tells us God gave us Pastors for the "perfecting of the saints"
That means if a christian is not in church, not only does God have a gift for him, he doesn't get to enjoy, he will also never be perfect (which in this case may mean mature, not sinlessly perfect)
Wanna hear a really cool thought?
Read Ephesian 5:25, look at who Christ died for, and then consider the salvation of one who doesn't want to belong to the church
