Here's the difference I think it makes whether we base our faith on the promise of eternity or the Good News of the Living God: it changes the way that we live. Or, one of those does.
Those who are in this thing for heaven don't really live any differently than those without that promise. They live their lives with one eye toward death and put all their eggs in a basket on the other side of the tomb, and in practical terms, it just doesn't matter a whole lot what I do on a Tuesday when heaven is forever and we aren't even there yet.
On the other hand, if the Living God is the foundation of your faith, it absolutely changes the way that you live. You start to see the kinds of things that Jesus saw - a short man climbing a tree, for instance, that wouldn't mean a whole lot to you if you didn't have your eyes open to the world you're living in. You start to hear the things that Jesus heard - voices crying for mercy from the side of the road. You start to feel the things that Jesus felt - like someone touching just the hem of your robe, trying to get a little taste of just what it is that makes you so confident, so at peace, so sure.
When Jesus is the model for your faith - the whole of Jesus and not just an empty tomb - it changes the way that you live in this world. It changes the things you choose to invest your time in. It changes the way that your heart responds to those around you. It changes the way that you see the world - and its inhabitants.
It changes everything.
I think this is the biggest problem that we have right now; this is the root of it, anyway. Jesus said they'll know we are Christians by our love. And yet, the world doesn't know this about us. Ask the world what a Christian is, and "someone who loves" is nowhere near the top of their list.
When we live just for heaven, it doesn't have to be. We focus either on works or on grace, but not a lot on love. There's no motivation for it. Eternity is eternity, and if all it takes to get there is to "believe" in Him...who has the energy for love?
But when He is the center of our faith - the Living God, among us, the Gospel, the Good News - then love is the heart of it all.
A few years ago, a coworker I was meeting for the first time (who worked in another building), came running excitedly up to me and said, "I was hoping I'd get to meet you!" And I wondered what in the world she meant, and she said, "You have always been so nice to me and my family, and I was just hoping I'd get to meet you and work with you!" I didn't know her or her family. I had no idea where I could have met them. She told me that they had come in while I was providing service in my job, and the way that I served them made such an impression that she never forgot it.
I tell that story not at all to brag on myself (Lord knows there are too many days where I don't get that right), but to say this: heaven doesn't make me live like that. Eternity doesn't give me the heart to love and to serve others. Jesus does that. The Gospel does that. The God who walks the streets and came here just to show us what love is does that.
So, I don't know, I just think that if more of us stopped living for heaven and started living for Jesus, it would change things in some very powerful ways.
Like I said at the beginning of this week, heaven is the thing I'm least certain of, and that's okay with me. I...don't need to know that. Because what I do know, what I'm most certain of, is love.
And that changes everything.