I know that everyone has something to do. There are more opportunities to serve than there is time to serve. So how do you choose where you're going to serve?
I've always had a problem with saying no when asked to serve, particularly when the expressed need was felt personally.
It was first my husband who put the governor on my wheels so to speak. I remember resenting it at first because being needed filled a hole in myself. But when you personally fill every hole that needs filling, you end up actually being swiss cheese yourself. So he instituted a policy of "everytime you say yes to one thing, you must say no to something else". The one for one policy helped me learn some priorities because I really had to want to do the "something" to be willing to give up another "something". Over time as I learned the whole prioritizing, I realized that my God-given talents were actually best used on somethings and weren't meant to be used at all on others.
For example, I love teaching the Bible. I currently teach a ladies' Bible study that I'm passionate about, and I pray that God is glorified in my service. I know myself to be completely dependent on Him for the time necessary to do all of the reading, study and preparation essential to being able to teach. And although God has given me a love for speaking in that it comes naturally and without too many nerves, I recognize that unless the Holy Spirit fills me for the teaching and prompts the hearts to receive, my words will fall empty.
On the other hand, one time I helped organize a consignment sale. I'm not nearly as talented with organizational skills as I desire to be, and the whole interpersonal ego/female dramas that occur with such a sale bring out the road rage person in me that I'd like to forget even exists. My "gift" for speaking becomes warped and sarcastic, certainly not glorifying to God at all. And although the money raised by the sale went to help worthy causes, I delighted in the personal gain the sale gave as well--maybe even too much.
Arguably, depending on God for both types of service is necessary. Humanly though, in the first case I know myself to be needy of His intervention, and constantly call out to Him for help. With the second case, I behaved in my own strength & all the stretch marks showed.
Conclusion: In having to choose where to serve, I wholeheartedly desire serving God in areas where I know myself to be most needful of His help. Otherwise I selfishly look to my own strengths, which end up not being strengths at all. My sin nature perverts them to weaknesses. But when I embrace my lack--of time, knowledge, skill, organization, wisdom, etc--God shows up gloriously to have His name proclaimed as the One who did in me and through me what I can not do in myself. It's scary, in my flesh, to be so "needy" of help when I'd rather feel myself capable. But when I feel myself to be "so capable", my flesh is scary.
Guess that's what Paul learned in 2 Corinthians 12:9 "And He has said to me, 'My grace is sufficient for you, for power is perfected in weakness." Most gladly, therefore, I will rather boast about my weaknesses, that the power of Christ may dwell in me."