We often have an excuse for why we cannot do something. (Let's be honest, it's not that we can't do something, we just don't want to.) A big reason people give for not living on mission is the feeling that they're not equipped to tell others about Jesus. This is kind of funny as we ask what would Jesus do. Telling others how to be saved was THE message from Jesus.
Often God planned circumstances will come our way and we think that God is done, the Gospel is over. Luke 24 describes such pity party. Jesus shows up and they have a long conversation. Jesus breaks bread and moves on. Jesus then again appears to his disciples explaining all that had to happen. As we read Luke 24:48-49 we see two things. Jesus says they are to be witnesses. Jesus says they will receive a helper. We learn in Acts the helper is the Holy Spirit. After acts one, when people accept that Jesus died on the cross and rose again on the third day, they're not only saved, but receive the Holy Spirit.
Successful evangelism is simply taking the initiate to share the Gospel in the power of the Holy Spirit and leaving the results to God. If you know Jesus rose from the dead after dying for your sin, you have all you need to be a witness. You have the Gospel. You have the Spirit. What we don't have are excuses.