In a way, not only is that person putting their faith in God. But they're putting their faith in you,that you'll pray for them. "I'll be praying for you" has become such a cliche, that I don't think alot of people are actually putting their promises into action. I don't think prayer is as meaningful to them as it is to some people. Prayer is very important to me. To me as a Christian, it shows that I'm putting all my faith in God. It's my way of expressing needs, concerns, praises to Him. It may be a small prayer request to you, but it could mean the world to someone else. Most likely when people ask for prayers, they're not telling you the whole story or they have alot more problems than they want to mention. So spend a little extra time praying for them.
God hears our prayers, God is faithful and prayers are very powerful! Pray for everyone!