When last night's debate moderator asked Al Gore to talk about global warming, Gore's response included the following scriptural reference: "In my faith tradition, it's written in the book of Matthew, where your heart is, there is your treasure also. And I believe that--that we ought to recognize the value to our children and grandchildren of taking steps that preserve the environment in a way that's good for them."
It was nice that Gore quoted Matthew 6:21 in support of taking care of the environment for the sake of our descendents, but he got the quote a bit wrong, and it was too bad Jesus wasn't there to complain he had been taken out of context. What Matthew 6:21 actually says is:
"Do not store up for yourselves treasures on earth, where moth and rust consume, and where thieves break in and steal; but store up for yourselves treasures in heaven where neither moth nor rust consumes and where thieves do not break in and steal. For where your treasure is, there your heart will be also."
So, first of all, Gore reversed the subject and object in the sentence he quoted--the Bible says "where your treasure is, there your heart will be also," but Gore remembered it as "where your heart is, there is your treasure." Which is a lovely sentiment, and possibly even true, but not what Jesus was trying to say.
Gore is arguing for a sort of storing up of treasures on earth, namely the preservation of our precious earth itself by means of environmentally friendly practices. One can argue that Gore is an illustration of the saying he (mis)quoted. There can be no doubt that Gore's heart is in the environmental issues. The causes of the earth and a cleaner environment to bequeath to our children are where his heart is, and so they are treasures he highly prizes. All this is fine, and very well intended, but is not at all the subject matter Jesus was addressing.
For one thing, Jesus says plainly here, "do NOT store up treasures on earth" that are subject to decay and loss. This could actually be read as an injunction against spending billions on the environment, since the earth inevitably will wear out, but probably it should not be. This aphorism of Jesus' is clearly about the amassing of personal wealth, as opposed to "storing up treasure in heaven." As is well known, Jesus takes a very dim view of building up one's personal portfolio and retirement account at the expense of doing good to others. Indeed, he saw wealth as a potential hindrance even to entering the Kingdom of God (see Matthew 19:23-24). The reference to moths suggests he had rich apparel in mind, and the reference to rust suggests coins, which in antiquity were normally stored in a personal storage box and sometimes buried in the ground, and did indeed tarnish under such conditions.
Storing up treasure in heaven is an interesting concept. It probably has to do with the sort of self-forgetful acts that Jesus is encouraging elsewhere in the Sermon on the Mount (Matthew 5:43-48). One could argue that if you work hard for a cleaner environment that ultimately only others in the future will finally benefit from, you are following Jesus' injunction to store up treasure in heaven or procure stars for one's heavenly crown by doing loving, self-forgetful acts here on earth.
But Jesus' real concern here is with human character and on the things we most highly prize. In Jesus' view, our hearts should be set on God, trusting God to take care of us. God should be the ultimate treasure on which we set our hearts. To set our hearts on something less than God, even if it is a good thing like the earth or a clean environment, is to turn an asset into a treasure, and the potential for idolatry (in this case the worship of material goods, or even the worship of the created order) is real.
Thus, while we may say that Gore's heart supports a noble cause, it is not the cause Jesus was talking about when Matthew 6:21 was first uttered. Jesus had very different treasures in mind. The ones he wanted us to avoid were material treasures (that is, storing up personal wealth), and the ones he wanted us to add to our credit column were self-forgetful acts that do not reflect the mistake of thinking this world is all we have in life, or have to live for.