How about a Atheist modifying Christian Belief?

I met a guy with brain damage, A Catholic. We discussed Bible some. I need to bring him around to the truth the of the earth because he believes it 7700 years old. Nope! I think I will pretty much confirm what he believes to also make it blend with science. I have never tried with brain damage but have with many mental problems much improve their intellect. Pretty fun helping in his own beliefs though. I don't want him to believe like me. I want him to make the book work and hold up to science. And it can be done. Not sure where that 7700 year thing came from. That's not Catholic. I believe Adventist influence. Finally someone that can get to my level with 3 university degrees. Intelligent people otherwise overlooked.