From a Reformed perspective, why do evangelism?

If you actually made it all the way through the previous post, then you'll understand that I wrote it because I wanted to share where I've been and where I'm going on this theological saga. After working through limited atonement (which, to me ended up being so closely tied to election that I no longer had an issue with it - I'll probably explain that better another day), then my next job was working back through what I've always believed and reviewing it in the light of what I was beginning to more fully understand about election. One of those things was evangelism. I knew I didn't want to be on the "hyper" side of calvinism. Obviously Jesus gave us a commission to go into all the world and preach the gospel. But what to say? "Jesus Christ died for you if you're one of the elect and if you're one of the elect you should consider this your notification that it's time to give your life over to Him." ?

This is the question Eric answered last week in for the Irish Calvinist's Q&A Friday. He quotes Spurgeon who (of course) says is better like this, “If God would have painted a yellow stripe on the backs of the elect I would go around lifting shirts. But since He didn’t I must preach `whosoever will’ and when `whosoever’ believes I know he is one of the elect.”