We had Steven Curtis Chapman's song, "When You Are a Soldier," in our wedding. I love this song! I changed up one line of the lyrics. Instead of "I'll be your friend if you win or if you're defeated...", I made had our singer do "I'll be yours if you win or if you're defeated."
I agree with other posters; Natalie Grant's song "When God Made You" is beautiful.
"I Will Be Here" by Steven Curtis Chapman is a great one too!