There is more to be said concerning Jesus in this blog. If we are to do evangelism, then we will find that Jesus not only did evangelism, but that he encouraged his disciples to do the same. Furthermore, there would be evidence that he wanted evangelism from believers in the post-apostolic era.
The first set of data then is what Jesus said concerning evangelism to others.
It is clear that he did ask his followers to take on the task. This is seen at a number of points.
At the call of the first disciples in Mk 1:16-20 which is retold by Matthew in Mt 4:18-22 the call included the statement that Peter, Andrew, James and John would fish for people. This means a shift of vocation from literal fishing to netting humans for the kingdom i.e. evangelism. In Luke's account of the call in Lk 5:1-11 of Peter the same emphasis is seen. Just as the disciples in this story take in an enormous yeild of fish from the deep water, the disciples will take in an enormous yield of human followers for Christ; this is reflected in Luke II (Acts) where the numbers of converts are staggering (e.g. 3000 in 2:41; 5000 in 4:4).
All three Synoptic Gospels (Mt 10, Mk 6, Lk 9) record the sending of the disciples in pairs to do a mission training trip. This involved going in pairs without financial support and preaching the message, healing the sick etc. They preached repentance, 'the kingdom of God is near' (i.e. the king is here). Thus they were trained and equiped to preach the message. In Lk 10 there is a further account of a larger group of 70 or 72 going out to preach the message. In each occasion their was a strong effect; especially Lk 10 where the disciples were amazed at what happened and Satan was defeated through their ministry.
Then we come to the post-resurrection period. A dominant issue in the Synoptic accounts is evangelism or mission to the world. In Matthew's account the disciples are told to go and make disciples and teaching them the full range of Jesus' teaching. This is a commission that includes evangelism, the first dimension of making disciples. Clearly the job includes more including baptism of the new converts and training them up to be full disciples through learning Jesus' teaching. The teaching is beautifully summarised in Matthew's Gospel i.e. learn this stuff and do it! New disciples are to be called as Peter, James, Andrew and John were called, to be fishers of people. They are to be trained through going on short-term mission journeys and hanging out with more experienced disciples who have learnt. It is a handing on of the baton type ministry.
Mark in 16:15-20 has a commission in the longer ending. I discuss the longer ending in an earlier blog if you have a look. I suggest that although it may not be original to the text, it is certainly still an early witness and to be taken seriously historically. It includes going and preaching the gospel and the promise of signs.
More important is the commission in Lk 24:46 where Jesus tells the disciples that they will be his witnesses, empowered by the Spirit, giving testimony to Jesus, calling people to repent and experience forgiveness in Christ. This again necessarily involves evangelism.
John in 20:21 has a commission whereby Jesus breathes on his disciples, giving them his Spirit as God breathed life into Adam in Genesis, and sending them as he had been sent himself. How had Jesus been sent? He had been sent by God from heaven as the pre-existent logos (word) and Son to redeem his fallen world corrupted by the forces of darkness. He preached and healed to save the lost through faith and so receive eternal life. Thus the disciples were commissioned by the resurrected Christ to do the same.
Jesus also linked his return to the completion of the task. In Mk 13:10 the gospel will be preached to all nations. In Mt 14:14 it will be preached to all nations before the end will come. Thus, the task is to get the message to every living person and every nation that all may know that Jesus has come and God's salvation is here. Incidentally, Mk 13:10 is very important in light of the probability that the longer ending is not original. It shows that there is a commission in Mark even if it is not specified. Then there is the story of the anointing of Jesus' feet by Mary of Bethany. Jesus in the Mt and Mk accounts (Mk 14:9; Mt 26:13) states that this story will be told throughout the world i.e. as we evangelise we will tell this story and many others.
It is clear from these accounts that Jesus wanted his followers to do evangelism. It is core business for us to share the faith. It is a non-negotiable. There are regular promises of persecution and struggle, but this is not to deter us.
So, it is patently clear from the Lord's teaching that believers are to do evangelism. There is no specification that only some are to do evangelism. It appears core to discipleship. It is the core and crux of mission which involves whole lives given over to God, demonstrated love, care for the needy and marginalised, social transformation, praying for people and seeing the power of God released, working for good in every part of the world to see God's Kingdom come. But at its heart is the sharing of the message so that people will be saved.