Wanting to be useful in this world, and use whatever abilities we may have, is a legitimate desire. We rightly want to be a force for good, to give freely to help mankind. And the life and teachings of Christ Jesus are our shining, forever example.
I have felt a sense of awe that when the tempter went at our Master to try to get him to magnify himself, pursue aims just for himself, he dealt with the evil immediately. He didn't fall for it, knew better than to have in thought anything other than seeing that his Father was glorified. In Jesus' case, and aspiration and actions were 100% pure.
For what it's worth to someone reading this blog, I have found that subjugating self to being about God's business doesn't take anything good away from us. It doesn't cause us to shut down and no long be able to employ talents. Not at all. Areas of usefulness will probably not be in the direction we once outlined for ourselves. But when we desire to serve Him, He sees to it that wider avenues of blessing others open up before us. They never fail to, when our motives are pure, and we want God to get the glory--be in the limelight, so to speak.
On the topic of laboring more selflessly, the woman who founded my religion has a statement that has always impressed me. She writes: "Goodness and benevolence never tire. They maintain themselves and others and never stop from exhaustion. He who is afraid of being too generous has lost the power of being magnanimous. The best man or woman is the most unselfed." ("First Church of Christ, Scientist, and Miscellany, page 165)
I am so thankful to have countless examples of selfless men and woman down the years who being Christ's followers, did the praying and struggling at times to overcome self, in order to be more useful to God and mankind.