on God and butterflies

I learned about the butterfly last week in my public speaking class. about how the caterpillar practically melts away and nothing is alive within the cocoon during metamorphosis. but then the cells build themselves back up into a butterfly.
I couldn't stop telling people about how cool this all was; I told everybody I could.
it was when I told a friend Saturday night that I realized how off I am. I am so stoked and willing to tell people about how utterly amazing the butterfly is and yet I cannot open up my mouth to talk about Jesus with the same excitement. I hardly talk about Him at all.
I think that is the case because I figure everybody has heard about God at some point or another and already have their minds made up about Him, whether they believe in Him or not.
but I guess it's all the same; everybody has some idea about how the caterpillar becomes a butterfly, but not everybody learns how nothing is alive, about how there's only liquid inside the chrysalis at some point during metamorphosis.
it's the same with God: everybody has heard about Him, or at least the idea of Him, but not everyone knows about His grace and mercy and love for us.
that's what I need to change, I need to get it out of my head that every single human being already knows what Jesus did for us and how we are truly dead, in this life and the next, if we choose not to invite Him to come into our hearts and save our poor, broken, and depraved souls.