So it is with the church.  When each gift-infested child of God uses their spiritual gift(s) “for the common good” then the church functions best.  Conversely, when a part of the body doesn’t use its gifting, the whole body suffers (verse 26).

That’s why Peter echoes Paul’s sentiments in 1 Peter 4:10 when he writes,

Each one should use whatever gift he has received to serve others, faithfully administering God’s grace in its various forms.

¡Wowzuh!  Each one (each member of the body of Christ…EVERY saved individual….) should use whatever gift he has received (the manifestation of the Spirit) to serve others (to function as a body part for the good of the body) faithfully administering God’s grace in its various forms.  In other words, when you choose to not exercise your gift, the aspect of God’s grace that could be shown through your giftedness is missing from the body.  If you are a sideline Christian you are depriving the rest of the body of your incredibly unique and God-given input.