The obvious reason for Christians to be involved in the environment is the original creation purpose of God (Gen.1:26, 2:15) ’Then God said, “Let us make man in our image, after our likeness. And let them have dominion over the fish of the sea and over the birds of the heavens and over the livestock and over all the earth and over every creeping thing that creeps on the earth.” … The Lord God took the man and put him in the Garden of Eden to work it and take care of it.’ Even though our sin has broken the world (Gen.3), the reconciliation in Messiah, bringing us back into relationship with the Creator also restores our responsibility as stewards of the earth He has given us to work and care for.
But there is more and it ties very closely with missions and evangelism. It is unfortunate that many well-meaning “development” programs of the past has instead resulted in large-scale ecological collapse and hunger.
In trying to help meet communities’ physical needs (e.g. the drilling of wells), the result can be overgrazing and ecological disaster. In this context, reaching people with the Good News will include making sure that we help them in way that really help, instead of having negative long-term effects. As stewards of God’s creation, it is important to use the available scientific knowledge (keeping in mind that it is still fallible) whenever we want to address the physical needs of the nations. Ecology and enviromental sciences are key to this process. (Of cource biblical principles (such as the sabbath year) found in Scripture, should also inform our decisions).
The second reason, is perhaps just as important. Even apart from His revelation in Scripture, God can be known (in part) through His creation (Rom.1, Ps. 8). Having the opportunity to introduce people to the wonders of creation/nature, also opens the door to talk about the One who created and designed it all. [Unfortunately, many Christians have been too intimidated by the theory of evolution to realize that it remains an inadequate (even if arguably the best currently known to science) explanation of creation.]
I, for one, were convinced of the majesty and power of God through my experience of nature, even before I knew Him. But to be able to expose people to the glory of God’s living creation, the fullness of the diversity that He created should be preserved for future generations. This is important both as a result of being disciples and fulfilling the original creation purpose of man, but also in the context of evangelism as a tool to introduce others to the living God. The hipocracy of Christians claiming to serve the true Creator of everything while at the same time destroying His handiwork/creation for selfish reasons (and even excusing their behaviour) have not been a witness that draw people to Jesus, but a stumbling block for many.