The story follows Horton, an elephant, who hears a voice coming from a speck on a flower. The speck, as it turns out, is an entire world. Only one person on "the speck", the mayor of Whoville(voiced by Steve Carell), can (or will) hear Horton. The mayor tells people of the voice, as does Horton in his world. Both find they are being ostracized for believing such a ridiculous thing. You can imagine the possibile outcomes when given such a storyline.
This movie is full of talking points regarding God and Christianity. It deals in detail what can happen when someone says they are "hearing a voice". When a person "hears from God" it is so intensely personal that he/she may do what seems to be extraorodinary or insane things. Others close to the person often respond in disbelief. The kangaroo in Horton says that if you can't see something, it doesn't exist. The mayor and Horton develop a relationship as they dialogue about their lives. Horton is very "God-like" in that he goes to great lengths to save "the speck" because his world wants to destroy it because they think he has lost his mind. Horton is a picture of what God has done in his pursuit of his creation, a pursuit that culminated in him becoming the saving sacrifice for it. I found it very interesting that in Horton Hears A Who that the Mayor's "only son" is the one who actually saves his world by being the one to break through and connect with Horton. How is our world (only a speck) saved? By the ONLY SON (John 3:16). He broke through and satisfied the wrath of God in his sacrifice on the cross, a debt that can never be repaid, but one that can be received as a gift of Grace.