We aren't told the truth about UFOs. Not all spacecraft you see in the sky are UFOs, but are Christships. Christship has been used to travel back in time to change history to fit the needs of certain groups of people. Those groups of people will use evil to get their way and control people who are not like them. The only thing standing between us and them is God.
We can't change the past, but we could change the future with the right people. We will stand with God and save the world from the evil we see.
