Paul does not rely on his superior gifts, talents, or education in order to administer the mystery of Gentile inclusion in God's plan. Instead, he recognizes that it is only the grace of God that has enabled him to take this message to the nations. In fact, he feels as though he is the least of the saints, probably because of his past persecuting believers, but that past does not disqualify him for exercising the grace given to him.
The reason this is so important is because God has a plan. His strategy is simple and profound. He will demonstrate His wisdom through His plan for the church.Our effectiveness is based in God's wisdom and Christ accomplished work. All we have to do is be obedient to take our place in His plan.
In the end, all creation, including the rulers and authorities of Heaven, will take notice of His work through those of us saved by grace. The Enemy may have laughed at the Great Commission, but one day he will recognize that the grace of God in broken vessels is more powerful and effective than he ever dreamed.
We don't have to go it alone either. Jesus has given us access to the God of wisdom who is demonstrating His glory through the church. At the end of the day, Paul, imprisoned for the gospel, is more afraid that the church will neglect the task at hand out of discouragement than he is concerned about even his own freedom.