The reason that the Holy Spirit imparts spiritual gifts to Christians is so that the body of Christ is built up (Ephesians 4:12), for the common good of the church (1Corinthians 12:7, 14:12) and "so that in all things God may be praised through Jesus Christ." (1 Peter 4:12). 

These three reasons signify that God wants Christians to be active in service and not still like stagnant water.  That is why we have been given gifts and if these gifts are not used for God's purposes, then they are utterly useless and meaningless.  And the gifts are not just the supposedly spectacular gifts but also the supposedly mundane!  Cleaning is as much a spiritual gift as preaching is!

As we are not to neglect our gifts, or let other Christians neglect their gifts, we are to fan the gifts into flame (2 Timothy1:6).  Much like blowing on embers and stirring them up will restart the flames of a fire!  To do this, as Christians, we are to employ the gifts faithfully and by asking God to continue their development, strengthening and for opportunities to use them! Seek gifts that build up others, commands Paul (1 Corinthians 14:1-12). Ask God faithfully for gifts that give opportunity for service to God and others!

Serving is never to be about what you and I can get out of it.  When that is the motive, God is not glorified. God's glory, honour and supremacy are to be the goal of a Christian's life.  Spiritual growth comes from serving rather than being served.  This is because what ever is given in service of God and others, your faith grows and Jesus Christ gives back even more.

Jesus speaking in Matthew 25:15-30 tells of the rewards for faithful service and the penalties for being faithless.  Serving others is a sign that you are trusting in and having faith in God.  It's a visible aspect of your invisible faith.  Service is the outward expression of your inner beliefs. Serving is an outward expression of your inner faith - an external working out of your inner salvation. Serving God and others is the mark of a spiritually mature (or spiritually maturing) Christian and through service, the greatest servant of all, Jesus Christ, is reflected in our lives. 

"For Jesus Christ, came to serve and give his very life for others" (Mark 10:45).  As Christians we are to be as Jesus Christ (Romans 8:28; Philippians 2:5) and to serve.  Yet if we are honest, we sometimes feel incapable, just as Moses did (Exodus 3).  When the church is built up, unity will inevitably prevail and be built up.