I know there's a scam here, but where is it?

Okay, recently I hit some serious financial hardship and against my better judgement I posted a digitalcharity page. Since then, unsurprisingly, my inbox has been bombarded with scam offers all written in broken English, refusing to use PayPal, and asking for money upfront for "transfer fees." But then I got one last night that I just can't figure out. I know it's a scam because it's written in typical broken English and the person claims to be a "man of God" but I just can't deduce where the scam lies and I'm curious. The amount I needed was $800. This man said he would send me a check or money order for some higher amount. Then he said cash it, keep the $800, and he will contact me about who to wire the remainder to. So what's the deal here? How am I being duped? Because it sounds too good to be true.