It was on the ninth orbit, during a live television broadcast, that the crew of Apollo 8 gave the world its Christmas present. The crew read in turn from the first ten verses of the Book of Genesis. “In the beginning God created the heavens and the earth. The earth was without form and void, and darkness was upon the face of the deep; and the Spirit of God was moving over the face of the waters. And God said, ‘Let there be light’; and there was light. And God saw that the light was good; and God separated the light from the darkness. God called the light Day, and the darkness he called Night. And there was evening and there was morning, one day. And God said, ‘Let there be a firmament in the midst of the waters, and let it separate the waters from the waters.’ And God made the firmament and separated the waters which were under the firmament from the waters which were above the firmament. And it was so. And God called the firmament Heaven. And there was evening and there was morning, a second day. And God said, ‘Let the waters under the heavens be gathered together into one place, and let the dry land appear.’ And it was so. God called the dry land Earth, and the waters that were gathered together he called Seas. And God saw that it was good.”
As a footnote, not everyone was impressed by the reading of Genesis. The militant atheist Madalyn Murray O'Hair later caused controversy by bringing a lawsuit against NASA over the reading from Genesis; she demanded that the courts ban US astronauts—who were all Government employees—from public prayer in space. (link)(via)
And that's why Buzz Aldrin's taking of communion on the well remembered moon landing mission Apollo 11 was never publicized... Not because of any official ban, but because of uneasyness towards the idea of how people would react.