Would the discovery of EXTRATERRESTRIAL LIFE completely debunk the bible and religion?
Not according to the Pope's astronomer. From the Huffington Post article:
“God is reason. If you reject reason, you are rejecting God,” Consolmagno said.
I'd even wager that the "big" religions (Catholics, Orthodox, etc.) already have a contingency plan worked out & locked up in a safe somewhere.
Top secret contingency plan? That would be to keep doing as they have always done. It would be the same as converting the first century gentiles. The same Vatican astronomer said that he would baptize E.T., upon her request.