There is a debate running through American Evangelicalism about the religious value of ecology. In short, should the church stick to proclaiming the core gospel, or do we have a responsibility to preach Green?
My first thought is that Christianity is a remarkably creation-affirming religion, so being Green does matter. The Gospel of the Christ starts with the goodness of creation. God poured joy and love into his Kingdom and creatures. And he made us, his image bearers, as physical, embodied creatures, tasked with the care and development of his world as a way to glorify him. And God declared it all very good. Of course, our sin and rebellion have broken and twisted God's world, but God does not leave us there. He himself took on flesh, redeeming us and beginning to set the world back in order. And God's story culminates with our bodily resurrection and the New Heavens & Earth--a re-establishment of creation in God's presence. God cares about his creation.
So when talking about the church's role in being Green, 'creation care' is indeed a part of who we are as God's people. But just green should the church be?
My second thought is that it would be helpful to distinguish which part of the church we're talking about. There's a difference between the official church (characterized by the offices and sacraments, for example) and the vocational church (characterized by the calling of all Jesus-followers to live out their citizenship in the Kingdom of God). In school, we called one the Church as Organization, and the other as Church as Organism.
I do believe the primary job of the Church as Organization is to proclaim the core gospel of Jesus Christ. The messiah is the center of history, and all worship and ministry points to him. That includes Word and Deed ministry, preaching in words and preaching in actions. It's not just sermonizing and Bible study, but also acts of mercy and encouragement of the wider church to use their vocations to glorify God. And that encouragement includes generally calling all people to honor and care for the cosmos, as Genesis says we were created to do.
Yet pastors, elders, and deacons don't usually know much about bioscience or economic policy, so there are limits to the direct involvement the Official Church. And there's much more to say about the gospel than just being Green. So, the Official church calls upon the Vocational Church--the Christian scientists, economists, and policy makers, for example--to integrate their faith and work. We look to them for the technical detail and policy choices that best honor God and His cosmos. Thus these Christians lead the Church as an Organism to the best ways to be Green for God.
So taken together, preachers and congregations should be talking about these issues, especially in their encouragement of Christians who have particular expertise. (This is true not only for being green, but all areas of life, from ecology to politics to business to art to history to sports, and beyond. It all belongs to God.)My third thought is that we can have confidence in the promises of God. As David Greusel's post Two Shades of Green, points out, we do not need to panic about lack of resources. David affirms our call to "creation care" as a Biblical mandate. But he goes on to reject a notion of doom that has occasionally woven through the Green debate. Pointing out that our God is a God of abundance, he says,
The message of global scarcity is a modern invention, and is not supported by what the Bible teaches. The problem we face is not so much a lack of resources as it is a lack of wisdom in their proper use. We are not running out of fresh water: the oceans are evaporating at the same rate they always have. We may hoard, waste, misuse, or pollute fresh water to our detriment, but we are not going to run out of it.He concludes, "Christians should embrace our role as careful and thoughtful stewards of this world while rejecting the fear-mongering that leads to unwise choices."