I first had doubts about the moon landing around 2015, but didn't come to a definitive conclusion. As the years went on, I was sympathetic to moon deniers because it was clear that those in power are lying about everything. If you catch someone in one lie, such as your wife, it's natural to evaluate other things they've stated to you as fact. I started to believe that it was more likely we didn't land on the moon than not.

I'm ready now to come out as a moon landing denier.

(after his moon trutherism is compared to post-modernism)

Denying Biblical teachings and scripture strikes me as a postmodern spirit. Questioning the existence of Holy truth and distrusting established Biblical facts are hallmarks of this philosophy. Ultimately, it has resulted in a rejection of the achievements and collective knowledge of God and His prophets. To call all of that into question seems like a play out of the leftist playbook. Deny the creation of God, glorify man's achievements, cut off your connection to the Holy Spirit, etc.

(After a poster tells him not to underestimate human ingenuity)

This is called "secular humanism", and is what has allowed us to inherit the world we have today. In other words, "human ingenuity" leads to gay pride, feminism, transgender children, deplatforming, fake news, etc. etc.