During a youth camp when I was in college, I went forward to pray for a young person. I heard God calling me through the preacher, and I experienced a burning in my heart while bursting into tears thanking God for His calling. When I was asked to preach and teach, God confirmed his calling through other people. Also, I saw people respond to the messages/lessons that I was led to share with them. The internal satisfaction I felt was also a testimony of this. I knew I was called as I saw God at work in my life, making things happen and opening a way for me to follow Him.