The idea of this is the importance of having the mind and heart filled with good things. Instead of letting evil thoughts invade the mind such as lust or pride, it's best to be filled with happy, positive, and loving thoughts. One verse that just came to mind is,
"Guard your heart above all else, for it determines the course of your life. (Proverbs 4:23)"
I think there are other verses that can relate to this picture too.
I struggle with this, especially with thoughts of pride and insecurities, but I'll keep loving God and believing in Him to lead me in having a pure heart.
Also, this is the first fully digital pic I've done in a long time. No ink, no scanner, nada! >:3 Yay~