If God is power hungry and out to get certain things in the world, his followers will do likewise. They will try to gain converts.
If our evangelism is driven by the need to "gain converts" it's a sure sign that we're serving a greedy god.
But if our God is a Fountain of sending love (as Donald Bloesch once put it) then mission will have nothing to do with "gaining" anything. Instead we will be offering Christ.