Are we allowed to believe the moon landings were faked by itself or do we have to believe in the flat earth also?
No one has to believe anything. Those who love the truth (and who realize that the world system is in the control of the enemy in this present darkness) usually undergo a slow process of waking up to the truth which is denied and hidden by enemies of the truth.
This is the case on many levels:
* waking up to the Truth of the Catholic Faith
* waking up to the problems with the conciliar church
* waking up to the truth that the earth is not billions of years old
* waking up to the truth that the sun is not at the center of the universe
* waking up to the fact that freemasons worship the sun
* waking up to the fact that NASA is freemasonic/ satanic
* waking up to the fact that geocentricism trumps heliocentricism
* waking up to the fact that NASA faked the moon landing
* waking up to the fact that NASA killed Gus Grissom
* waking up to the fact that "the big blue marble" is photoshopped
Those who really really love the truth and do not care what others think about them will have the courage to continue on in their search for the truth.
Others will find out that they care too much what others think of them. They will argue loudly against a theory which they have not researched, while swallowing whole a nonsense theory peddled by freemasons.