I imagine it would be quite the shift in attitude once we make contact with life forms from other planets. I'm not saying it hasn't happened, it just may not have been made public knowledge. Like I've mentioned before who knows what NASA hasn't made public with information they have. I could think that most of humanity could be accepting of extra-terrestial contact but my main concern whether it would be peaceful or war like.
The various religions may have to sit down to have a serious re-evaluation of their teachings and core beliefs. But I don't see any discovery or contact with life beyond Earth being a serious threat other than who we get in touch with. It's only been in the last four centuries that it's become common knowledge that Earth is not the center of the Universe. So some problems might need to be dealt with as we get off our high horses.But instead of thinking we're more special than thought, think of what information could be shared with friendly ET's.
With all the planets that exist in all the galaxies, some would be more than capable of sustaining some form of life as we know it. I've thought for years that it's pretty vain and egotistical on our part to think Earth in the only planet to have life on it. But I don't see the walls of churches, mosques or temples crumbling as they still could be of value.
The fact that we're not alone in the Universe shouldn't be that much of a shock.It's probable that most Earthlings believe in life outside on other planets but may keep quiet because of the fear of ridicule or retribution. Confirmation of discovery of life on other planets means accepting it and moving on. It doesn't make us less special, it means that we are all equally special in the eyes of whatever God is out there.