Lady Gaga's "Born this Way" has a pretty strong message to love yourself no matter who you are.  Her most apparent audience here is young people struggling with their sexual identity, especially those in the LGBT community.

"There's nothing wrong with loving who you are"
She said, "'Cause he made you perfect, babe"
"So hold your head up girl and you'll go far,

I'm beautiful in my way
'Cause God makes no mistakes
I'm on the right track, baby
I was born this way

"Imagine" by John Lennon is a song with a message and the message is consistently spread throughout the song. In the chorus and in each verse the message is the same: the world could be significantly different if we simply looked at it differently.

"Firework: by Katy Perry has a message and some nice figurative language, including simile, metaphor, and onomatopoeia.  The song suggests that you should not feel "like a paper bag drifting throuhg the wind wanting to start again."  Rather you should feel good about yourself, because "baby, you're a firework...show 'em what your worth."  The lyrics suggest self-empowerment, and the song's huge popularity reveals that many people could identify with Perry's message.