For many, there would be humility and a sense of awe. The universe is big and the potential for many sextillion of habitable planets (that's a billion times a trillion). And the idea that we're not alone!
For some of the newly humbled, they may realize that their small interpretation of a holy text was wrong. Those who do not find humility, may lose faith, because the arrogance of knowing truth before it is found will leave them vulnerable in that false knowledge.
For some, there would be increased greed. Goody! New worlds to conquer.
Perhaps the most noble change would be a gathering of resources to investigate more closely that other life. Now, that I like.