There is no one else to carry out the Biblical function of Evangelism but us, Evangelism is for Saved People.
Jesus gave the command to his disciples who saw him as lord and savior. The truth is that if you are not a part of the Church, then evangelism is not a function that you should be carrying out and you have no power or authority from God to do so. You first have to be evangelized before you can evangelize others.
In the book of Acts 19:14-15, seven sons of a Jewish chief priest named sceva tried to set free a demon possessed man which did not turn out the way they may have expected. They said “I command you in the name of Jesus, whom Paul preaches, to come out!” . The New living translation called their command an incantation, which means a spell or magic formula; the Demon said, “Jesus I know and Paul I know, but who are you?”. They were ravished with a beating and were lucky to have survived. It is interesting that the demon used two different Greek words define his knowledge of Jesus and Paul. He said “ I know Jesus” the Greek word (Ginosko. know, aware of) he was a Demon, a Fallen Angel, so he well knew the Son of God and he also said “I know Paul” (epistamai) to recognize, to be acquainted with. The Demon knew Jesus and came to be acquainted with Paul but could not fathom knowing these seven vagabond Jews….the Demon recognized that they were imposters. If they had authority from God, the demon could never have attacked them and gave them a fine flogging.
The account of the great commission in Mark 16 tells us that believers will also have power over unclean spirits and work miraculous signs; the sons of sceva had none of these for they had not accepted Christ, they were merely using the name, not having the power. They were trodding on dangerous grounds, and it is sad to say they are more imposters now in Christendom that ever before.