There is nothing stereotyped about God's dealings with His children. Therefore, we must not by our prejudices and preconceptions make watertight compartments for the working out His Spirit, either in our own lives or in the lives of others. We must leave God free to work as He wills and to leave what evidence He pleases of the work He does.
The author tells a story wherein a missionary friend of his was invited by unbelievers on a train ride to play cards. The friend declined, saying that he did not bring his hands with him. He explained to the astonished group that the hands attached to what they saw as his body belonged to the Lord, and he was thereby able to explain the Gospel.
The author nicely encapsulates Paul's overarching intent in his letter to Corinth, to impress upon those in the church infatuated with the gifts of the Spirit a greater awestruck awareness of His presence in and among them. The author then illustrates thusly: if we have but a few coins, we may carry them lightly with little concern as to whether we lose them. But if we are aware that we carry a great sum, we will carry it with great care. How much more the Treasure of the Holy Spirit within the earthen vessel of our bodies?