Not only are we but a spec of dust, but all life from the smallest bacteria, to the insects, to the animals are also specs of dust. All life has value. We often consider that the value of animals derive from what they can provide. Horses provide transportation, cows provide milk and meet, dogs and cats provide companionship. However, every life has an inherent value that is derived not only from its purpose, but also from its creator. Every life is significant.
Not only life, but all objects have value. From the grain of sand to the highest mountain, all things have this inherent value derived from the creator. Each spec of cosmic dust, each asteroid, each planet, each star all have value derived from the creator.
Christianity teaches that humans also have value derived from the creator. But, we have an additional value because we are created in the image of the creator. We have an additional value that exists because we are created in the image of the Triune God. Regardless of our efforts, our social status, or our physical or mental ability, we all are created with this image.
It is this value that creates for us a system of ethics. When we consider the animals and features of the planet on which we live, we realize all are worthy of protection. When we see any human, we see a sibling created in the same image as ourselves. This provides our guidance for what is right and wrong. As culture and history changes, this guidance stays constant. As we understand the effects of our actions on the environment, this guidance provides direction.
Many in Christian history have misunderstood this guidance, and have attempted to make a solid list of right and wrong based on a particular point in history. The challenge is that our view of the world and our place in it is constantly adapting, being enhanced with new understandings and new knowledge. As our view changes, our interpretation of the guidance has changed, but the foundation upon which it is built should never change.