Going Out to Save the World?

I think I might have talked about this before but I was reminded again recently that lots of Christians are going out to save the world. Strangely, although our intentions might be good, we are often, I think, guilty of bypassing God's will and thinking we know best - exactly as sinners do all the time!! As somebody once said (origin unknown) "The road to hell is paved with good intentions".
We only have one model for mission activity explicitly stated in the Bible in Acts 13:1-3: "In the church at Antioch there were prophets and teachers: Barnabas, Simeon called Niger, Lucius of Cyrene, Manaen (who had been brought up with Herod the tetrarch) and Saul. While they were worshiping the Lord and fasting, the Holy Spirit said, "Set apart for me Barnabas and Saul for the work to which I have called them." So after they had fasted and prayed, they placed their hands on them and sent them off." (NIV)
It is clear from this model that 1) The people were sent FROM the church, not from their own ideas, 2) They were sent BY the Holy Spirit 3) The people who were sent had not decided to go anywhere before the Holy Spirit sent them. Whether the fasting was just a means to focus prayer or a requirement is for your own quiet times.
Sadly many people totally circumvent this. Without it being Spirit led, we are in danger of not hearing his voice but the voice of our own soulish intent to do good stuff for God. It should not be the case of deciding I want to go to such and such a country so I will approach the church and prayer for confirmation, it should be the normal and ongoing purpose of the church to prayer and be prepared for the Holy Spirit to send people. This avoids any egos being involved and also more importantly allows God to do things in his perfect timing rather than our rubbish timing.
Of course you could argue that just because this is the only model in scripture doesn't mean it is the only one to be used but as far as I can see, this is a good model and doesn't seem to have any shortcomings so why invent another model? Unless of course it is to suit a soulish intention!