"This is the generation of the great LEVIATHAN, or rather, to speak more reverently of that mortal god, to which we own under the immortal God, our peace and defense." -Thomas Hobbes: Leviathan
It seems to me that contemporary Christianity is made up of three fundamentally inconsistent propositions with regards to consciousness and the soul.
(1) We should care for “creation” and the welfare for animals who can experience pain and suffering and we should minimise their suffering.
(2) Our conscious experiences is the defining feature of our being images of God and possessing an immaterial soul.
(3) Being images of God or possessing souls is considered to be purely a human phenomenon, animals are not made in the image of God nor do they possess souls.
Thus, the three propositions are inconsistent and we must reject one of them. Let us see what comes out of rejecting each one by one.
(A) The Cartesian Solution: We maintain (2) and (3) and argue that yes, conscious experience is a unique feature of being ensouled and images of God and only humans are ensouled and images of God, ergo, (1) is false and animals have no conscious experience nor do they feel anything but are nothing more than meat machines or organic robots. (Descartes was the one who popularised this idea)
(B) The Christian materialist/Lutheran Solution: We maintain (1) and (3) and reject (2) that consciousness or being ensouled as defining or constituting what it means to be images of God, that is, being conscious is simply a biological subsystem and has nothing to do with immaterial souls or images of God. The fact that humans are images of God is not a matter of possessing immaterial souls or consciousness but a matter of theology and not metaphysics (e.g. such as possessing the righteousness of God, knowledge of God, worship, etc), therefore not something we possess “by default” of being conscious beings.
(C) The Pagan Solution: We maintain (1) and (2) and reject (3) that only humans are images of God and that all creation somehow “images” God or is some form of expression of the divine and that includes animals, a sort of Hegelian the whole universe is sort of a soul or mind struggling to be conscious of itself.
I personally take (B) although it would be quite interesting to see how would anyone else grapple with the difficulties…