When a Republican president signed the Endangered Species Act into law in 1973, he probably could not have dreamed how effective it would be: In the 45 years since, the law has prevented the extinction of more than 99 percent of the species that have been listed for protection. But it can do only so much, it applies only in our country and the law is under attack.

Some lawmakers in Congress are working to undermine the Endangered Species Act even as the threat of extinction for many species is greatly increasing. In a study published in the journal Science Advances in 2015, biologists found that the Earth is losing mammal species at 20 to 100 times the rate of the past. Human impacts are the prime reason for these unprecedented losses.

So, it makes no sense that members of Congress are trying to dismantle this critically important law. They are disguising their intentions with language about “modernizing” the law. This is code for making it easier to destroy habitat in which fish swim and birds sing, even “unimportant” little fish and “obscure” little birds. Who needs them, anyway? What are they doing for us?

The Endangered Species Act works, mostly in the quiet background. It has protected marquee animals like manatees, eagles, grizzly bears and peregrine falcons, as well as species that you and I will never see.

People of faith around the world know that there is more to life than what we can measure, hear or see. There is a creed we recite every Sunday in my church that begins: “We believe in one God … maker of all that is, seen and unseen.” Just because we can’t see it, does that make the unseen unimportant?

When I entered seminary as a 50-something, I had spent 25 years as a professional fly-fishing instructor and guide. For that reason, I read Genesis not just with my head, but also with a heart deepened by years on the water and in the woods, and by walking many times through “the lilies of the field” on my way to a river. In this first book of the Jewish and Christian Bibles, humanity is given dominion over the divine gifts of waters, over plants and “trees of every kind” and over “everything that has the breath of life.”

These are the gifts you see when you fish with eagles above you, when you walk through wildflowers, when you close your eyes and hear thesound of birds. As Mainers, we are blessed today with hundreds of nesting pairs of bald eagles, up from fewer than 30 in the 1960s. The Endangered Species Act has played a vital role in the revival of the species.

When I think of the Eden story in Genesis, I picture more than the garden that God planted there and its two solitary humans. I think of the teeming life just beyond it, filled with the sounds and colors of creation, surrounded by countless species of incomprehensible diversity and mystery.

You don’t have to believe in the factuality of the story to imagine the beauty of that world. That beauty surrounds us still. But it faces pressures, and those pressures confront us with challenges and questions.

For the children who will be born 100 years from now, what will the creation that surrounds them look and sound like? Will it still teem with God’s creatures, sounds and colors, both heard and unheard, seen and unseen? Will we have provided the stewardship needed to pass on to future generations the wondrous world that was passed on to us?

The Endangered Species Act is one tool that will help ensure that creatures large and small, known and unknown, are given a chance to thrive beyond our days.

I pray that Maine’s congressional delegation recognizes and values the importance of this landmark law, which was enacted unanimously in the U.S. Senate in 1973. May they defend it from harm as we collectively seek to minimize the harm we impose upon the world around us.

Macauley Lord is a resident of Brunswick, an Episcopal chaplain and a fly-fishing guide.