It is an amazing reminder that no matter how good things get in the Christian life and no matter how much joy and celebration we have in Christ there are only the firstfruits of what is to be a much larger crop. What we experience now with the Holy Spirit is only but a tiny fraction of that which is to come.
It is these firstfruits that symbolize the promise of more to come. We have but a taste of the Kingdom of God and of adoption by God. If you believe that Jesus is powerful to act through His Spirit in this present day and age, just wait until you see the Son of Man in all his glory ascended to the right hand of the Father!
Indeed the Holy Spirit is our deposit and guarantee of the salvation and redemption of our bodies that is to come. Though in Christ we have already been made children of the promise and heirs to the kingdom of God, we also eagerly await the fullness of God's glory and harvest. Those who possess it groan with eager expectation and a deep longing for intimacy with our Father in heaven. Do you feel it? That ineffable pull in your gut that longs for more something? My friends, more is out there and it's coming.