Without giving you an exact figure, I can tell you that the list of "things that encourage me about evangelism" turned out to be longer than I was expecting. The difficulty comes in deciding where to start. I think it's fairly reasonable to begin with some things that Jesus said. So here we go:
"Behold, I have given you authority to tread on serpents and scorpions, and over all the power of the enemy, and nothing shall hurt you. Nevertheless, do not rejoice in this, that the spirits are subject to you, but rejoice that your names are written in heaven." (Luke 10:19-20)
“All authority in heaven and on earth has been given to me. Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age.” (Matthew 28:18-20)
“This, then, is how you should pray: Our Father in heaven, hallowed be your name, your kingdom come, your will be done, on earth as it is in heaven." (Matthew 6:9-10)
If we fall into the trap of seeing evangelism as something we have to do, something that is awkward, embarrassing and won't really work anyway, it's useful to get Jesus' perspective on the matter.
Firstly, Jesus doesn't use the word "evangelism", which might be significant. I mean, the word does have a potentially off-putting archaic religious feel to it. The very word is a little intimidating, so it might be reassuring to remember that Jesus didn't tell his followers to engage in a programme of evangelisation. Nor did he say, "harken unto me, as I now bestow upon ye THE GREAT COMMISSION". Jesus never sounds like he's trying to establish a religious tradition. He gets to the heart of the matter without the ecclesiastical bumf.
So, do we have to? Well, Jesus did say "therefore go", which sounds like a command to me. But he also makes it sound pretty exciting with the whole stomping on snakes and scorpions stuff. The way Jesus presents evangelism, it's more like something we get to do. A privilege. An opportunity. An adventure.
Jesus also talks about evangelism like it really works - as if we might actually succeed. In fact, it seems like we should expect significant spiritual events to take place as a result of our obedience to Jesus.
Jesus didn't suggest we pray for God's kingdom to come because God was struggling with the process and needed our help. Isn't it because God's kingdom is coming, and he wants us to get involved?