It's a big girl world now, full of big girl things

So I have to write a sermon for August, the weekend I get back from Mexico. Something tells me to wait until after the trip, because something there is bound to inspire me, but I just don't know.  I've also been wondering if it's really something I can do. My majors were really keen on it when they approached me about it, but I feel like they have a lot more faith in me than I deserve.  My love for the Lord should make me confident in the message I've been asked to give, right?
The more I think about it, the more I know exactly what I need to speak about.
Sorry for the pointless post.