Churchill covered up a UFO incident because he feared public panic and a loss of faith in religion.
His viewpoint was absurd. Well, “absurd” might be too strong of a word to use. Those who think that now are wrong. Though I can understand why some people in government might have felt that way.
If alien life exists on other worlds, it doesn’t change anything about Christianity or faith in Christ. The existence of alien life doesn’t prove or disprove anything in regard to the Bible. The Bible does not tell us one way or the other if there is life on other planets.
If aliens landed on the lawn of the White House and they disembarked and waved to all of us, it wouldn’t cause me to doubt even the smallest ideal or principle of my faith in Jesus. It wouldn’t bring the text of the Bible into doubt in anyway.