If you are fresh out of college, list it on the resume. Your resume is an account of what you've done so far in your adult life, and your mission is a part of that. Plus, most people will notice a 2-year gap in your life if you don't list it. List it, as it is an honorable thing you did.

Now, imo, you don't bring it up. You're there to get a job. Sell the skills you learned in college and any internships, etc. If they bring it up, then answer truthfully and feel free to list any qualities gained that make you more qualified for the job.

IMO, if you're the one to bring it up, it can make you look like a religious nut.