From when God created the first human beings to when those beings sinned against Him, people from all nations were brought together to help save the earth and bring lives to Christ. Little steps and big steps were executed to further the kingdom of God, the examples could be recalled as preaching in a church or being a missionary, as well as simple instructions that is when God tells you not to do something or to do something.
We are called to further the kingdom of God for God. To live our life to the fullest is what He wants us to live. He wants people in the world to love Him and follow Him for forever. We are commissioned. That means we are ordered to an important task. Jesus was commissioned to preach and heal, die on the cross, and rise again to prove Himself. We are called to lead just like Jesus so others can experience that very same thing. The lost need our help. Especially your help. Your story can perhaps save someone's life! That was why they can witness just like you did!