My professional ministry (ministry I got paid for) began with college students. There was nothing else I wanted to do. I gave my heart to Christ in college and knew this is a very seminal time in the life of young people. I knew that a mentor, Bible teacher and fellow encourager in the Lord would be able to see changes in young people which would last for decades. There was nothing else I would rather do. God had other plans.
I left college ministry to work with Single adults. I loved singles. There were so many unique ministry opportunities. Many of them had children, many were pre-marriage (not married but would be married some day), many would never marry and several were widowed. Their ages were from eighteen to seventy-seven. I enjoyed working with Singles. God still had other plans.
I got the opportunity to preach and something changed in my heart. I really enjoyed it. People encouraged me. I set out to pray and see if this was a new direction in my life. It wasn't long before God clearly spoke. He told me clearly that He wanted me to preach. I asked if I could preach with the same force that another preacher I knew had. He asked if I was willing to drink from the cup that God had him drink from. I said yes without knowing what I was saying.
I prayed to become a senior pastor so that I could preach every week for the next eight years and three months. I prayed in the morning and in the evening. This was one of the most precious times in my life. God used this time to help me mature.
I decided that I needed to act like I was preaching even if I didn't get the chance. I prepared sermons that I never expected to preach. Weekly I prepared sermons. This preparation helped me when I did become a senior pastor. Also, during this time I was ready to preach at a moment's notice. I got the opportunity to do so often. I think God honored my preparation.
Start preparing sermons that you have no reason to believe you will ever preach if you think that God is calling you to preach. Then watch how God will give you the opportunity to preach those sermons.
God not only calls you but He prepares you. He not only prepares you but gives you opportunities. He not only gives you opportunities but blesses you in these opportunities. He changes you to be a vessel that will be fully useful for His purposes. He changes you and brings the joy of doing what you were created to do.
2 Timothy 4:2 (NIV)
2 Preach the Word; be prepared in season and out of season; correct, rebuke and encourage--with great patience and careful instruction.