You can make an incredible difference in the world simply by being you. Consider the relationships that you have already developed, and the scope of influence (family, friends, neighbors, colleagues, etc.) available to you at this time. You likely possess more influence than you may have initially realized!
You don’t necessarily have to be rich, famous, or some sort of politician in order to make a difference in the world (although the Lord may work through these folks, too). One thing you must do, though, is this: You must care – that is, you must be genuinely concerned for the welfare of other people. If you are willing to do this, then God can and will use you to accomplish great things within the sphere of influence that He has already given to you.
If you haven’t done so already, simply resolve to be open and available, and leave everything else in the Lord’s capable hands. Test Him in this area and watch what happens! After all, God cares, too. 🙂