I have the same feeling before I go to mission, I just believe because I grow in this church and I happen to have a borrowed testimony. I think the best thing to do is what my bishop have asked to do. He said that I must gain testimony by reading the scripture especially the book of mormon, and ask God himself if this church is true. I prayed hard for a couple of days. Then I just felt that IT IS THE ONLY TRUE CHURCH. The holy ghost let me feel it. The warmth, sudden gush of joy and something more that really will touch your heart. I can't argue that this is the true church unless you have prayed with sincerest heart and humbly to God and ask for the truth. I know God will answer you, just wait. You will just get confused if you rely on the knowledge given by man.