Christian theology revolves around the notion that God created this planet, and the people on it, deliberately, and that he loves us as his own children (despite a rather nasty effort at drowning the population once upon a time). Some fundamentalists believe literally in the Bible, but even liberal Christians tend to believe that God made creation with us in mind, and that he loves each of us in a personal and highly attentive way. God notices each sparrow's fall, Jesus assures us, and we humans are worth so much more than mere sparrows.
This sort of thinking made sense back when people believed the Earth was the center of the universe, that the visible planets revolved around the Earth, and that stars were set "in the vault of the sky to give light on the earth, to govern the day and the night, and to separate light from darkness." But our understanding of the universe now is somewhat different, and decidedly clearer, than that which our nomadic forebears possessed.
According to this article on Universe Today, the Milky Way (which is an average-sized galaxy) is believed to consist of approximately 400 billion stars. The observable universe (that part of the universe which we can see) contains more than 170 billion galaxies, which means there are approximately a septillion stars in the universe-- a number so large that human minds can't begin to comprehend it. Even Douglas Adams, genius that he was, didn't quite get the idea across with his famous explanation that space is "vastly, hugely, mindbogglingly big."
The article goes on to explain that the universe may be much bigger than we can actually observe-- possibly infinitely large. And then there are all those other possible universes as well. So why do we still imagine God created all this impossible vastness just for us? It seems pretty clear that we're no more than a very small and very irrelevant grain of sand in the cosmos. If there is a god, it seems highly unlikely he created all this for us, and that our tiny planet is somehow central to his great plan.
In fact, it seems profoundly unlikely this hypothetical god has even noticed us.