This little verse gets quoted out of context a lot. It is used to justify bizzare plans and dreams, as well as to suggest that every Christian should be rich and healthly all the time. Not only are such applications without any support in Scripture, they are completely out of the context of this passage.
In the previous verses, Paul lists a variety of circumstances that he had faced, from proverty to wealth, learning to be "content" in each of these developments. Then he notes that he "can do all things" through the strength that the Lord provides during conflicting circumstances.
The "do" of this text is the prevailing of the power of God in which and by which we minister. "Not that we are sufficient of ourselves to think any thing as of ourselves; but our sufficiency is of God; Who also hath made us able ministers of the new testament" (2 Corinthians 3:5-6).
The early church experienced a stunning growth in converts as it preached and testified of the resurrected Christ. This result, however, is due to the fact that the Word of God grew "mightily . . . and prevailed" (Acts 19:20).
Our fight is not a physical one. We wrestle against the great spiritual powers of wickedness that have their source in the heavenlies. The history of God's people is replete with the battle that was begun in the Garden of Eden. Adam and Eve lost because they sought to deal with the issue on their own. We win or prevail only when we arm ourselves with God's armor and become "strong in the Lord, and in the power of his might." (Ephesians 6:10). HMM III