Paul, called to be an apostle of Jesus Christ through the will of God... -1 Corinthians 1:1 (NKJV)
Within our human hearts, there's a natural longing to belong to a cause that's greater than us. For those who never encounter God through Jesus Christ, this internal itch is destined to go unscratched. But those who know Christ discover they play a part in a story with an eternal scope.
Paul taps into this truth as he begins his first letter to the Church of Corinth . He starts out by identifying himself as "Paul, called to be an apostle." This reveals that God had an important purpose and plan for Paul's life. God didn't just save Paul for the purpose of letting him sit around on some spiritual shelf. Instead, He desired to involve Paul in a plan that would prove to satisfy his built-in desire for purpose, direction, and meaning.
But we need to understand that this wasn't just something special or unique between God and Paul. The Bible tells us that all Christians have a divine commission and calling that has been placed upon their lives (Ephesians 4:1).
In this regard, the Christian's identity is completely different from those around them. They enjoy a sense of purpose because they've chosen to play a part in God's master plan. Unfortunately, we tend to forget this fact from time to time, and consequently we tend to relate more to the world's emptiness than the fulfillment that God desires for us.
Because we've been called by Christ to play a part in His grand design, our lives are filled with purpose, direction, and meaning.