Acts 1:8 8But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth.1
Back when I was a college student I went on a mission trip to Zambia, Africa. To be honest, I was scared out of my wits about going. But I had prayed and felt that God had led me to go on this trip. You see I had this fear of speaking in public. In fact I avoided speech class in college because of my fear. Anyway before going on this trip I had spoken in front of a group of people just a few times and was terrified each time I had spoken. Well just as our plane was descending into Lusaka, the capital of Zambia, Brett, my director leaned his seat back and asked me to to be ready to share my testimony after we landed. He didn't know what we would be doing, or how long it would be before we were to be out speaking to people, but he wanted me ready. I prayed for help.
The second day there we went to a high school of over 1,000 students. They had a convocation where we were the program, the American students from the USA. As part of the program three of us were to share a portion of the gospel message. I remember sitting on the stage and praying that God would give me the strength and words to say. I told Him I was willing to get up in front of everyone and make a fool of myself if I couldn't get any words out. My time came and I went to up to the podium. I opened my mouth and God gave me the words to say. I was amazed and relieved. This went on the whole summer long. I saw God work time after time and we saw over 1,600 students place their faith in Christ. I saw first hand the power of God at work.
1 Acts 1:8, NIV.