Here is a tug-of-war.
At one end of the rope is our common conviction that life—our life, other lives, life in general—is a good thing. For many, this conviction is little more than a cliche, a toast, an instinct for self-preservation that includes just familiar faces. For others with a religious orientation, the concept of life is much more vast, one face of the cycle of birth and death, a name for both flesh and spirit. Both groups, though, lean hard towards life and away from the state of dust and stones. We all ally ourselves with being alive and, in the abstract at least, with all things that are alive.
But pulling hard at the other end of the rope are the distinctions that we make every day between lives that we value and those we value very little or not at all. We favor people who are similar to us, we belittle others, and we are indifferent, sometimes fatally so, to many others. We accept abortion but oppose capital punishment, or vice-versa. We cuddle some animals, save others from extinction, eat a few, exterminate many. We value plants for providing us with food or a desirable environment, but the life of an individual plant in and of itself has no status for us. When it comes to actual living things, we have favorites and losers, the innocents, the inconvenient, and the unacceptable, with life and death consequences.
In this tug-of-war between reverence for all life and differentiation among lives, it’s differentiation that usually wins. This isn’t surprising. We must draw distinctions each day in order to stay alive, deciding who to align with and who to oppose, what to eat and what to cut down, spray or ignore. Most people go through most days with no interest in revering life universally. We toast our health and long life and then eat our chicken dinner. We wake up in the morning feeling glad to be alive, we send a contribution to help poor children, we call the exterminator, and we pull dandelions. Even the conscientiously devout weed their gardens. None of that seems contradictory.
You might expect that after declaring that we value life above all else, we would place being alive above any other feature of a thing, and we would care for that thing because, no matter what else it is, it is alive. Insects might be repulsive, but they would be precious because they live. Plants might be so abundant that lawns and streets could be overgrown but their right to life would be defended while we starved from trying to subsist on dead animals and fallen fruit. Obviously this is not how things go.
Perhaps tug-of-war is not the best metaphor. Compartmentalization might be a better label. Reverence for life and preference for some lives are not strictly incompatible (we may hasten the death of a beloved relative to stop their pain) but mostly we put them in separate compartments.
And what we also do is take reverence out of its compartment every so often when the time seems right and try to move society a step in its direction. We join forces to extend a better life to those of other ethnicities or social classes or genders or sexual orientation—as well as to some animals, to fetuses, to endangered plants. Protective reverence for all life may be beyond our reach, but we put it to powerful use when we are able. We may draw grim, unfair distinctions among other lives too easily, but as long as we remain a little uneasy that we do so, reverence for all life remains a cause that can be advanced.